FaceLake ® FL400 Pulse Oximeter Fingertip with Carrying Case, Batteries, Lanyard, and Warranty (Blue) Specifications and Accessories The FL400 package comes with: 2x AAA Batteries Included Carry Case and Lanyard Included Device specifications are listed as: Batteries must be facing in opposite direction to function. Dimensions: 3” x 1.75” x 5" Operating temperature 5°C to 40°C Storage temperature -40°C to 60°C Operating humidity 15-80% RH ORDER NOW https://amzn.to/2LqJb3c