Alpha Fit 221 Shrink Tubing 3/4&rdquo; Diameter 4' Length 600V 2:1 Shrink Ratio Polyolefin Black Material: Cross Linked Polyolefin, 3/4 Diameter Minimum Supplied ID(In) 0.75 Maximum Recovered ID (In) 0.375 Nominal Recovered Wall Thickness(In) 0.030 Color: Black