1/2" (ID) x 100 feet Length Spool 2:1 Ratio Polyolefin Black Heat Shrink TubingCLICK HERE for Heat Shrink in Different Sizes, Colors, & LengthsHigh Quality Flexible Polyolefin Features & Specifications: Color: Black Inner Diameter(ID): 1/2" Length: 100 Feet (Spool) Shrink Ratio: 2:1 (Shrinks to 1/2 of its original diameter) Highly Flame Retardant UL224 125° C UL Listed & CSA Certified RoHS Compliance Operating Temperature: -55° C to +135° C (-67° To 275° F) Maximum Continious use Temperature: 135° C (275° F) Voltage Rating: 600V Applications: Electrical Insulation, Strain Relief, Cable Bonding, Color-Coding, Wire Marking, Corrosion Protection, Solder Insulation, Wire Bunding & more.