【4:1 super performance】:a shrink ratio of 4:1 means that it shrinks to 4 times its original diameter and allows a tight seal.It is currently the new product with the highest shrinkage rate on the market. 【More inner adhesive】:our heat shrink tubes contain a special inner adhesive that overflows after shrinking the hose and connects firmly to the cable to ensure a tight connection and at the same time play the role of waterproof and dust-proof insulation to achieve effective protection. 【Premium material】:our heat shrink tubes are made of high-quality,flame-retardant polyolefin material, which has the advantages of good electrical insulation,good tightness and corrosion resistance,which ensures a long service life and reliable performance. 【Easy to use】:these heat shrink tubing are easy to use and can be shrunk in seconds.Simply cover the bare wire section with the heat shrink tubing and heat with a soldering iron or heat gun. 【Technical data】:temperature min.- 55 °C,max. + 135 °C,shrink temperature 90 °C Are you looking to fix a damaged wire, seal out moisture, or provide enhanced strain relief? waterproof heat shrink tubing is an easy to use solution that can be used in automotive, marine, hobby RC, and home electrical wiring projects. When heat is applied, this wire shrink wrap tubing will recover to a 1/4 of its original diameter. Its high recovery ratio makes it possible to repair most damaged cable jackets without removing large connectors. Therefore, 4:1 shrink ratio tubing can be used in significantly more applications compared to 2:1 and 3:1 shrink ratio tubing. Additionally, 4:1 marine heat-shrink tubing shrinks around wires and terminals more tightly, eliminating any air gaps.