Dymo XTL label makers print directly on continuous Heat-Shrink Tubes. Heat-Shrink Tubes provide insulation when shrunk down and ensure a secure fit on wires and cables with a 3:1 shrink ratio. Constructed of flame-retardant polyolefin sleeves and tested to industry standards. Meets MIL-M-81531, MIL-STD-202G, SAE-DTL- 23053/5 (Class 1 & 3). UL recognized as a component to UL 224.