JT&T Products (4051H) - Assorted 3/16", 1/4", 3/8" Diameter, Heat Shrink Tubing, Black - 4" Cuts, 8 Pcs. Irradiated, Flexible, Polyolefin Heat Shrink Tubing is intended for general purpose applications requiring recognition by military and industrial specifications UL listed and meets MIL-1-23053/5 specifications Temperature Rating of -55C (-67F) to 135C (275F) and up to 300C (572F) for short durations Shrink Temperature is 121C (250F) and Shrink Ratio is 2 to 4 (8) 4" Pcs.