Plumbeeze Heavy Duty Heat Shrink Kits series are made of flexible cross-linked polyolefin heat shrinkable tubing. This tubing is suitable for applications up to 600 volts providing excellent waterproof insulating and environmental sealing protection for splices, connections, and jacket repairs. The high impact and abrasion resistance of this heavy wall tubing provides the highest level of mechanical durability. When heated above 120°C (250°F) there is a 3:1 shrink ratio.