3M’s 4-ft., black, heat-shrink tubing is made of cross-linked polyolefin. It has heavy tube walls lined with adhesive. It can be used in temperatures from -67° to 230°F with wire sizes from 2 AWG to 4/0 AWG at a max of 1,000V. The minimum temperature for shrinking is 250°F. After shrinking, the tube wall is 0.120 in. thick.