The Heat Shrink Tubing and Sleeves 309-40323 from HellermannTyton is a flexible, heat shrinkable tubing designed with a 2:1 shrink ratio. It is made of transparent polyolefin shrink and has a 3.2 mm expanded inner diameter as well as a 1.6 +/- 0.1 mm recovery inner diameter. This product offers superior mechanical and electrical protection, as well as environmental contact and resistance against fluid, abrasion, and sunlight. It provides an airtight, watertight seal and can be used on both insulated and uninsulated wires and connectors. Additionally, it is UL recognized and CSA accepted.