Dual Wall Flame Retarded Heat Shrink Tubing Military Grade Heat Shrink : MIL-DTL 23053/4 Underwriters Lab : UL 224 CSA : 600V, 125 Degrees Celsius Heat Shrink Tubings - Insulate, Protect & Identify SPDW heat shrink is ideal for sealing connector to cable transitions and similar moisture proofing applications with adhesive lined tubing. SPDW is approved to MIL-DTL 23053/4 and UL 224. Shrinktek Dual Wall Flame Retarded Heat Shrink Tubing Thorne & Derrick are the largest UK distributor of heat shrink tubings and sleevings including 3M, Panduit, Hellermann Tyton, DSG Canusa, Shrinktek and Thomas & Betts. Stock lines include thin, medium and thick wall adhesive lined heat shrink sleeves and moulded shapes (heat shrink cable caps, cable breakouts and cable boots) - insulate, seal, protect with heat shrinkable tubing.