Ancor Heat Shrink Snap Plugs feature a heat-activated adhesive built into the sleeve of the heat shrink tubing. When heated, the connector shrinks to form a watertight seal, as well as providing ultimate vibration and strain relief. Each snap plug is constructed from pure copper for maximum current flow and is tin-plated to resist corrosion from salt and moisture. A brazed seam ensures maximum strength. UL listed and CSA recognized.