127 pcs Heat Shrink Polyolefin Tubing 2:1 Electrical Wire Connection Sleeve Cable Insulation Tube Kit (7 Sizes)For use in electrical systems to repair, insulate and add strength to wiring Tubes shrink to half diameter when heated to provide a secure seal Includes 127pcs: 30pcs 2. 0x40mm, 25pcs 2. 5x40mm, 20pcs 3. 5x40mm, 20pcs 5. 0x40mm, 16pcs 7. 0x80mm, 8pcs 10. 0x80mm, 8pcs 13. 0x85mm 70C minimum shrink 110C full shrink 55C to 125C operating temperature bulk package, no box Use a heat gun or lighter at about 1 2 inch distance to shrink the tube. Don't touch