3:1 SHRINK RATIO - Recovers to 1/3 of its diameter, and makes a tight seal. Eliminates the problem of 2:1 tubing not shrinking tight enough. GLUE INSIDE - When heat is applied, adhesive comes out and seals the connection, creating waterproof and long-lasting insulation. OF SIZES - We have included 7 most commonly used diameters ranging from 3/32inch to 3/4inch. Shrink tubing is precut to 3.5 inches. EASY TO USE - heat shrink tube over your connection point and apply heat. Professional connections seconds. DUAL WALL TUBING - Outer wall provides abrasion resistance. Inner wall creates waterproof seal and strain relief. Heat shrink ratio: 3:1 Operating Temperature: -55 Celsius to and 125 Celsius Minimum Shrinkage Temp: 70 Celsius Full Shrinkage Temp: 110Celsius maximum Dielectric strength: 15 kV / mm : Retardant When heat is applied, this wire shrink wrap tubing will to a 1/3 of its diameter. Its high recovery ratio makes it possible to repair most damaged cable jackets without removing connectors. Therefore, 3:1 shrink ratio tubing can be used in significantly more applications compared to 2:1 shrink ratio tubing. Additionally, 3:1 marine heat-shrink tubing shrinks around wires and terminals more tightly, eliminating any air spaces. Colour:black Material:polyolefin Package Contents: 1 x Heat Shrink Tubing Kit (180 PCS) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.