The 342-20020 with Heat Shrink Tubing and Sleeves is designed to meet the highest quality standards. It is a heat shrinkable tubing made from a polyolefin based material, which provides a simple and economical way to insulate, seal, and protect wires against dust, moisture, and abrasion. It is flame retardant and impermeable to water and moisture, making it ideal for a variety of applications. This tubing has a 2:1 VG-Norm Shrink Ratio of 6.4/3.2, meaning that it will shrink back to half of its original diameter when exposed to heat. This product is manufactured by HellermannTyton, a world leader in professional electrical connectors, tools, and other industrial solutions.