These virtually indestructible covers are designed to stop vandalism and accidental damage of fire alarm devices like horns, speakers, and strobes. They are made of thick, clear polycarbonate plastic backed by a three year warranty against breakage. Various models are available for different device types and installation needs, including flush mount, surface mount, and weather resistant options. Spacers and backboxes can accommodate larger devices and electrical connections.

1. FIRE PRODUCTS
For more information, call 1-800-888-4784 (4STI) or visit www.sti-usa.com
KEY features
General Information
· Proven effective for more than
30 years in helping stop false fire
alarms without restricting legitimate
alarms.
· Can be used as a guard against
physical damage to a manual pull
station, with or without the optional
warning horn.
· Protect devices such as EPOs, call
boxes, telephones and emergency
shutdowns by changing the color
and messaging.
· Three year guarantee against
breakage of polycarbonate in
normal use (one year on electro
mechanical and electronic
components).
Design
· Larger sizes and surface mounted
pull stations accommodated with
STI-3100 conduit spacer.
· Weather models have closed cell
gaskets.
· The Stopper II design is a registered
trademark of Safety Technology
International, Inc.
Construction
· UL Listed to U.S. and Canadian
safety standards (also for custom
labeling).
Installation
· When covering a pull station
outside, UL requires stations to be
listed for outdoor use.
· Typical working properties of
polycarbonate are -40° to 250°F
(-40° to 121°C).
Electronics
· Power source is a 9V DC alkaline
battery included on standard
Stopper II (remote powered unit
available).
· “RC” models include one Form “C”
dry relay contact and are capable
of operating from 9-24V DC remote
power or 9V DC battery power.
Options
· Optional horn has a choice of 95 or
105 dB at one foot.
· Standard red units have “In Case
of Fire...” label unless specified with
“no label” or “custom label” (extra
charge for custom label).
· Horn housing is available in red,
blue, green or yellow with optional
custom labeling.
Product Overview
These virtually indestructible covers (slotted for horn or speaker units and solid for
strobe-only alarms) are designed to stop vandalism and accidental damage. Molded
of clear, thick, UV-stabilized polycarbonate material, they are backed by a three year
guarantee against breakage in normal use. Slots in the STI-1210, 1215, 1217 and 1219
allow the horn to be heard. The STI-1221, 1225, 1227 and 1229 are for strobes only.
Many tough, clear spacers are available for larger strobe/horn units, retrofits, surface-
mount and weather resistant applications. For the STI-1210/1221 series, spacer A has
a four inch deep enclosed backbox, spacer B has an enclosed backbox molded with
an integral double-gang outlet box. Spacer C has an open back for retrofit applications.
Spacer D accommodates deeper units and applications with exposed conduit electrical
connections. Spacer E has an open back frame for flush-mount applications. An
appliance mounting plate comes with the STI-1219/1229. Unique Enviro Kits are
available for extreme conditions where dampness or water is present.
STI horn/strobe
damage StopperS®
·
STI-1210B STI-1221E
STI-1217 STI-1225
ADACompliant
ADACompliant
STI-1210 AND
STI-1221 ONLY

2. Printed in U.S.A., © 1987-2009 Safety Technology International, Inc.
2306 Airport Road
Waterford, Michigan
48327, USA
Tel: 248-673-9898
Fax: 248-673-1246
Toll-free: 800-888-4784
info@sti-usa.com
www.sti-usa.com
Unit 49G Pipers Road
Park Farm Industrial Estate
Redditch, Worcestershire
B98 OHU England
Tel: 44 (0) 1527 520 999
Fax: 44 (0) 1527 501 999
www.sti-europe.com
06/09Subject to change without notice.
STI Horn/Strobe Damage Stoppers®
Dimensions and Technical Information
models available
STI-1210A Horn/Strobe Damage Stopper cover and enclosed
backbox, 4” deep, weather resistant
STI-1210B Horn/Strobe Damage Stopper cover and enclosed
backbox with double-gang outlet box
STI-1210C Horn/Strobe Damage Stopper cover open backbox
with external mounting tabs
STI-1210D Horn/Strobe Damage Stopper cover and open
backbox with conduit knockout
STI-1210E Horn/Strobe Damage Stopper cover and open
backbox for flush mount
STI-1221A Strobe Damage Stopper cover and enclosed
backbox, 4” deep, weatherproof with drain vent,
Type 3R
STI-1221A4X Strobe Damage Stopper cover and enclosed
backbox, 4” deep, weatherproof, Type 4X
STI-1221B Strobe Damage Stopper cover and solid enclosed
backbox and double-gang outlet box
STI-1221C Strobe Damage Stopper cover and open backbox
with external mounting tabs
STI-1221D Strobe Damage Stopper cover and open backbox
with conduit knockout
STI-1221E Strobe Damage Stopper cover and open backbox
for flush mount
SUB-84 Tamper resistant screws
SUB-121 Enviro Kit for D and E models
SUB-122 Enviro Kit for B and C models
SUB-06297D “D” spacer only
SUB-06297E “E” spacer only
STI-1283 Backplate for “D” and “E” models
19038 Bit for tamper resistant screws
SUB-6297B20 3/4” conduit hub for “B” and “C” backbox
outdoor rated)
approvals warranty
TESTING
It has been tested and approved or listed by:
· Underwriter Laboratories and Canadian UL File S7025
· cUL approval for UL 1638 only
· CSFM needs local approval
· MEA STI-1210 and STI-1221 series only
· UL Listed for fire voice speakers for STI-1210 series only
· ADA Compliant
Performance Review Manufacturer
STI-1210 SERIES
ADT SECURITY (ADTG1-V Series), EST/EDWARDS(G1-V Series,
G1-HV Series, G1-HOV Series, EG1-V Series, EG1-HV Series,
EG1-HOV Series), HONEYWELL (XLSG1-V, XLSG1-HV, XLSG1-
HOV Series), MIRCOM (MG1-V, MG1-HV, MG1-HOV Series),
SIEMENS (G1-V Series), ZITON PTY LTD (ZG1-V Series)
EST/EDWARDS (2440S, 202 Series), HONEYWELL (XLS202
Series), MIRCOM (MS Series), MIRTONE (MG1-V Series),
SIEMENS (202 Series)
AMSECO-(SL24W-153075 CLEAR, A, B, G or R,
SL24C-3075110 A, B, G or R, CSL24W-A, B, G or R, CSL24C-A,
B, G or R), MIRCOM (FS-240), POTTER ELECTRIC (AS-24-
153075R, AS-24-153075W)SYSTEM SENSOR (SS24110ADA)
SYSTEM SENSOR (P2, PC2, P4, PC4, SX, SC)
STI-1221 SERIES
AMSECO-(SL24W-153075 CLEAR, A, B, G or R,
SL24C-3075110 A, B, G or R, CSL24W-A, B, G or R, CSL24C-A,
B, G or R), MIRCOM (FS-240), POTTER ELECTRIC (AS-24-
153075R, AS-24-153075W)
DETECTION SYSTEMS (GES24 Series), GENTEX (GES24
Series), HARRINGTON SIGNAL (GES24 Series), NATIONAL
TIME SIGNAL (GES24 Series), SECUTRON (GES24 Series)
ADT SECURITY (ADTG1-V Series), EST/EDWARDS (G1-V Series,
G1-HV Series, G1-HOV Series, EG1-V Series, EG1-HV Series,
EG1-HOV Series), HONEYWELL (XLSG1-V Series, XLSG1-HV
Series, XLSG1-HOV Series), MIRCOM (MG1-V, MG1-HV, MG1-
HOV Series), SIEMENS (G1-V Series), ZITON PTY LTD. (ZG1-V
Series)
AMESCO (SL24W-153075), SYSTEM SENSOR (SS24110ADA)
EST/EDWARDS (2440S, 202 Series), HONEYWELL (XLS202
Series), MIRCOM (MS Series), MIRTONE (MG1-V Series),
SIEMENS (202 Series)
FARADAY LLC (2700)
SYSTEM SENSOR (P2, PC2, P4, PC4, SX, SC)
Light Loss
%
40%
43%
47%
53%
26%
31%
34%
37%
45%
57%
61%
Use of horn/strobe cover on audible device decreases the sound output by 6dB(A).
DEPTH
6.25 in.(159mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1210A
A SPACER
DEPTH
6.25 in.(159mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1221A
DEPTH
3.5 in.(89mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1210B
B SPACER
DEPTH
3.5 in.(89mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1221B
DEPTH
4.75 in.(120mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1221C
C SPACER
DEPTH
4.75 in.(120mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1210C
DEPTH
5.75 in.(146mm)
WIDTH
6.5 in.(165mm)
STI-1210D
HEIGHT
8.5 in.(216mm)
D SPACER
DEPTH
5.75 in.(146mm)
WIDTH
6.5 in.(165mm)
STI-1221D
HEIGHT
8.5 in.(216mm)
WIDTH
6.5 in.(165mm)
HEIGH
8.5 in.(216
DEPTH
4 in.(102mm)
WIDTH
6.5 in.(165mm)
HEIGH
8.5 in.(216
DEPTH
4 in.(102mm)
DEPTH
WIDTH
HEIGHT
STI-1210
DEPTH
3.5 in.(89mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1210B
DEPTH
4.75 in.(120
WIDTH
6.5 in.(165m
8.5 i
STI-1210 SERIES H
DEPTH
6.25 in.(159mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1210A
DEPTH
6.25 in.(159mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1210A
A SPACER
DEPTH
6.25 in.(159mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1221A
DEPTH
3.5 in.(89mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1210B
B SPACER
DEPTH
3.5 in.(89mm)
WIDTH
6.5 in.(165mm)
HEIGHT
8.5 in.(216mm)
STI-1221B
4.7
6.
4.7
6.
DEPTH
WIDTH
HEIGHT
STI-1210
DEPTH
WIDTH
HEIGHT
STI-1221
STI-1210 Series Horn/Strobe Covers STI-1221 Series Strobe Covers
H W D H W D
8.5 in. 6.5 in. 6.25 in. 8.5 in. 6.5 in. 6.25in.
(216mm) (165mm) (159mm) (216mm) (165mm) (159mm)
8.5 in. 6.5 in. 3.5 in. 8.5 in. 6.5 in. 3.5 in.
(216mm) (165mm) (89mm) (216mm) (165mm) (89mm)
8.5 in. 6.5 in. 4.75 in. 8.5 in. 6.5 in. 4.75 in.
(216mm) (165mm) (120mm) (216mm) (165mm) (120mm)
8.5 in. 6.5 in. 5.75 in. 8.5 in. 6.5 in. 5.75 in.
(216mm) (165mm) (146mm) (216mm) (165mm) (146mm)
8.5 in. 6.5 in. 4 in. 8.5 in. 6.5 in. 4 in.
(216mm) (165mm) (102mm) (216mm) (165mm) (102mm)
6
B SPACER C SPACER D SPACER E SPACERA SPACER
STI-1221A
DEPTH
6.25 in.(159
WIDTH
6.5 in.(165
8.5
DEPTH
6.25 in.(159m
WIDTH
6.5 in.(165m
8.5
DEPTH
WIDTH
HEIGHT
STI-1221
Enclosed backbox, 4” deep (includes neoprene gasket)
Enclosed backbox, 4” deep Type 4X (includes silicone gasket)
Enclosed backbox with double-gang outlet box
Open backbox with external mounting tabs
Open backbox with conduit knockout
Open backbox for flush mount
SPACER DESCRIPTION
WARRANTY
Three year guarantee against breakage of polycarbonate in normal use.
Spacer
A
B
C
D
E
A
A4X
B
C
D
E

3. Printed in U.S.A., © 1987-2009 Safety Technology International, Inc.
2306 Airport Road
Waterford, Michigan
48327, USA
Tel: 248-673-9898
Fax: 248-673-1246
Toll-free: 800-888-4784
info@sti-usa.com
www.sti-usa.com
Unit 49G Pipers Road
Park Farm Industrial Estate
Redditch, Worcestershire
B98 OHU England
Tel: 44 (0) 1527 520 999
Fax: 44 (0) 1527 501 999
www.sti-europe.com
06/09Subject to change without notice.
STI Horn/Strobe Damage Stoppers®
Dimensions and Technical Information
models available
STI-1215 Stopper Dome for Horn/ Speaker/Strobe for flush
mount
STI-1217 Stopper Dome for Horn/ Speaker/Strobe with open
backbox
STI-1219 Stopper Dome for Horn/ Speaker/Strobe with
enclosed backbox
STI-1225 Stopper Dome for Strobe only flush mount
STI-1227 Stopper Dome for Strobe only with open backbox
STI-1229* Stopper Dome for strobe only with enclosed
backbox, Type 4X
STI-1212 Spacer kit
STI-1222 Enclosed backbox for Stopper Dome
STI-1284 Single Gang Mounting Adapter for STI-1219 and
STI-1229
SUB-84 Tamper resistant screws
SUB-123 Enviro Kit includes three gaskets
19038 Bit for tamper resistant screws
approvals warranty
TESTING
It has been tested and approved or listed by:
· Underwriter Laboratories and Canadian UL File S7025
· cUL approval for UL 1638 only
· CSFM needs local approval
· For hazardous applications in Canada, to meet cUL, your strobe
must be ULC Listed
· ADA Compliant
Performance Review Manufacturer
STI-1215/17/19 SERIES
ADT SECURITY (ADTG1-V Series), EST/EDWARDS (G1-V Series,
G1-HV Series, G1-HOV Series, EG1-V Series, EG1-HV Series, EG1-
HOV Series), HONEYWELL (XLSG1-V Series, XLSG1-HV Series,
XLSG1-HOV Series), MIRCOM (MG1-V Series, MG1-HV Series,
MG1-HOV Series), MIRTONE (MG1-V Series), SIEMENS (G1-V
Series), ZITON PTY LTD (ZG1-V SERIES)
AMSECO (SL24W-153075), AMSECO-COLORED LENSES
(SL24W-153075 A, B, G or R, SL24C-3075110 A, B, G or R,
CSL24W-A, B, G or R, CSL24C-A, B, G or R), MIRCOM (FS-240),
POTTER ELECTRIC (AS-24-153075R, AS-24-153075W)
FARADAY (2700), SIEMENS (U-MCS Series)
DETECTION SYSTEMS (GES24 Series, GES24-15/75), GENTEX
(GES24 Series, GES224-15/75), HARRINGTON SIGNAL (GES24
Series, GES24-15/75), NATIONAL TIME SIGNAL (GES24 Series,
GES24-15/75), SECUTRON (GES24 Series, GES24-15/75)
SYSTEM SENSOR (SS24110ADA)
EST/EDWARDS (2440S Series, 202 Series), HONEYWELL (XLS202
Series), MIRCOM (MS Series), SIEMENS (202 Series)
WHEELOCK (RSS-24MCW)
WHEELOCK (RSS-24MCC)
SYSTEM SENSOR (P2, PC2, P4, PC4, SX, SC)
STI-1225/27/29 SERIES
SYSTEM SENSOR (P2, PC2, P4, PC4, SX, SC)
WHEELOCK (RSS-24MCW)
ADT SECURITY (ADTG1-V Series), EST/EDWARDS (G1-V Series,
G1-HV Series, G1-HOV Series, EG1-V Series, EG1-HV Series, EG1-
HOV Series), HONEYWELL (XLSG1-V Series, XLSG1-HV Series,
XLSG1-HOV Series), MIRCOM (MG1-V Series, MG1-HV Series,
MG1-HOV Series), MIRTONE (MG1-V Series), SIEMENS (G1-V
Series), ZITON PTY LTD. (ZG1-V SERIES)
FARADAY (2700), SIEMENS (U-MCS Series)
EST/EDWARDS (2440S Series, 202 Series), HONEYWELL (XLS202
Series), MIRCOM (MS Series), SIEMENS (202 Series)
WHEELOCK (RSS-24MCC)
SYSTEM SENSOR (SS24110ADA)
AMSECO (SL24W-153075), AMSECO-COLORED LENSES
(SL24W-153075 A, B, G or R, SL24C-3075110 A, B, G or
R, CSL24W-A, B, G or R, CSL24C-A, B, G or R) SCM24W),
DETECTION SYSTEMS (GES24 Series, GES24-15/75), GENTEX
(GES24 Series, GES224-15/75), HARRINGTON SIGNAL (GES24
Series, GES24-15/75), HONEYWELL (XLSG1-HOV Series),
MIRCOM (FS-240), NATIONAL TIME SIGNAL (GES24 Series,
GES24-15/75), POTTER ELECTRIC (AS-24-153075R, AS-24-
153075W), SECUTRON (GES24 Series, GES24-15/75)
Light Loss
%
20%
22%
23%
27%
26%
33%
34%
36%
39%
28%
31%
32%
33%
34%
35%
36%
37%
Sound loss for STI-1215, 1217 and 1219
Horns: Amseco Audible Horn Sounders - 6.2 dBA
Speakers: Siemens Adapter Series (0.5, 1, or 2 watt taps only) - 4.1 dBA
*Hazardous models available. See STI-1229.
4.50 in.(114mm)
9.37 in.(238mm) 9.37 in.(238mm)
2.87 in.(73mm)
4.25 in.(108mm)
9.37 in.(238mm)
2.87 in.(73mm)
MOUNTING
PLATE
STOPPER DOME DIMENSIONS
STI-1219 / STI-1229
STI-1217 / STI-1227
STI-1215 / STI-1225
7.87 in.
(199mm)
4.50 in.(114mm)
9.37 in.(238mm)
9.37 in.(238mm)
2.87 in.(73mm)
4.25 in.
(108mm)
7.87 in.(199mm)
9.37 in.(238mm)
2.87 in.(73mm)
7.37 in.(187mm)
MOUNTING
PLATE
1.63 in.
(41mm)
1225 STROBE ONLY
PROTECTIVE COVER
SPACER
STI 1227
GASKET BETWEEN COVER AND SPACER
1215 HORN/STROBE
PROTECTIVE COVER
SPACER
STI 1217
SPACER
USED IF CONDUIT
IS NOT PRESENT
CONDUIT SEALING
GASKET
ADHESIVE BACKED
GASKET BETWEEN
SPACER MOUNTING
SURFACE
STI-1225 STROBE ONLY
PROTECTIVE COVER
SPACER
STI-1227
IRO KIT GASKET BETWEEN COVER AND SPACER
WARRANTY
Three year guarantee against breakage of polycarbonate in normal use.

4. Printed in U.S.A., © 1987-2009 Safety Technology International, Inc.
2306 Airport Road
Waterford, Michigan
48327, USA
Tel: 248-673-9898
Fax: 248-673-1246
Toll-free: 800-888-4784
info@sti-usa.com
www.sti-usa.com
Unit 49G Pipers Road
Park Farm Industrial Estate
Redditch, Worcestershire
B98 OHU England
Tel: 44 (0) 1527 520 999
Fax: 44 (0) 1527 501 999
www.sti-europe.com
06/09Subject to change without notice.
STI Horn/Strobe Damage Stoppers®
Dimensions and Technical Information
O RING GASKET
(1) PROVIDED
ADHESIVE BACKED GASKET
(1) PROVIDED
DIA.
E SPACER
(PRE-EXISTING)
O RING GASKET
(1) PROVIDED
EXISTING
INSERT
CONDUIT GASKET
(1) PROVIDED
D SPACER
(PRE-EXISTING)
ADHESIVE
BACKED GASKET
(1) PROVIDED
SHOWN.
BE INSTALLED IN SLOT #1 AS
EXISTING RETAINING CLIP MUST
WHEN USING 629761 GASKET
LOCATED IN THIS AREA
1210C1221C
629761 RING GASKET
(1) PROVIDED
(1) PROVIDED
STI-3002 ADHESIVE BACKED GASKET
1210B1221B
(1) PROVIDED
629761 RING GASKET
629763
STANDOFF BLOCKS (4) PROVIDED
NOTE: MUST BE USED IN AREAS
WHERE FREQUENT WASH
DOWNS OCCUR
B SPACER
(PRE-EXISTING)
C SPACER
(PRE-EXISTING)
“O” RING GASKET
(1) PROVIDED
NOTE: MUST BE USED IN AREAS
WHERE FREQUENT WASH
DOWNS OCCUR
(4) PROVIDED
STANDOFF BLOCKS
B SPACER
(PRE-EXISTING)
C SPACER
(PRE-EXISTING)
“O” RING GASKET
(1) PROVIDED
ADHESIVE BACKED GASKET
(1) PROVIDED
STROBE PROTECTIVE COVER
(PRE-EXISTING)
ENVIRO KIT GASKET
BETWEEN COVER AND SPACER
(1) PROVIDED
SPACER (PRE-EXISTING)
USED IF CONDUIT
IS NOT PRESENT
(PRE-EXISTING)
ENVIRO KIT CONDUIT
SEALING GASKET
(1) PROVIDED
ENVIRO KIT ADHESIVE BACKED
GASKET BETWEEN SPACER
AND MOUNTING SURFACE
(1) PROVIDED
SOCKET HEAD SCREW
(6) PROVIDED
WASHER
O RING GASKET
(1) PROVIDED
ADHESIVE BACKED GASKET
(1) PROVIDED
629761 O
RING GASKET
6297316 ADHESIVE
BACKED GASKET
(4) 19033 ANCHORS (4) 19013 SCREWS 10 X 1 1/2
E SPACER
(PRE-EXISTING)
O RING GASKET
(1) PROVIDED
EXISTING
INSERT
CONDUIT GASKET
(1) PROVIDED
D SPACER
(PRE-EXISTING)
ADHESIVE
BACKED GASKET
(1) PROVIDED
STI-1210E
STI-1221E
STI-1210B
STI-1221B
SUB-121
SUB-122
SUB-123
EXISTING
COVERFASTENERS
SOCKET HEAD SCREW
RETAINING CLIP
GASKET629761
SLOT #2
SLOT #1
1210B1221B
(1) PROVIDED
629761 GASKET
629763 STANDOFF BLOCKS (4) PROVIDED
NOTE: MUST BE USED IN AREAS
WHERE FREQUENT WASH
DOWNS OCCUR
B SPACER
(PRE-EXISTING)
“O” RING GA
(1) PROVIDE
WHEN USING 629761 GASKET
EXISTING RETAINING CLIP
MUST BE INSTALLED IN
SLOT #1 AS SHOWN.