Heat Shrink Fabric are hollow pieces of polyolefin, polyester, or polyethylene that become smaller in size as they become warm. Most often used as insulation material when connecting wires together. Other uses are grouping wires together, insulate items from mechanical wear, and rattle suppression. With a 2 to 1 or 3 to 1 shrinking ratio in lengths from 1.772” (45.00 mm) to 1640.4’ (500.0 m) in supplied diameters of 0.24” (6.1 mm) to 3.94” (100.0 mm).