Marine Grade Heat Shrink - Adhesive Lined - Wirefy 1/2" Heat Shrink, 50 Ft. Roll 3:1 SHRINK RATIO - Recovers to 1/3 of its original 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. This creates waterproof and long-lasting insulation. EASY TO USE - Simply slide heat shrink tube over your connection point and apply heat. Make professional insulated connections in seconds. DUAL WALL TUBING - Provides enhanced protection from wear and tear. Industrial grade tubing is resistant to fluids, heat, and mechanical stretch. 1/2 INCH (12.7mm) SHRINK TUBING DIAMETER - Get the exact diameter you need. 50 Feet of shrink tubing will last through many projects.