This is a resistant shrink tubing with the internal adhesive layer. When heat is applied, shrink tubing recovers and the internal adhesive layer melts. A small fillet of clear adhesive (about 1 mm wide) becomes visible at the end of the heated tubing. When cooled down, it forms a rigid seal. Heat activated glue strongly adheres to wires, terminals or any other surfaces. When adhesive flows, it pushes the air out and fills any gaps between the wire and the tubing, which makes the connection resistant. For best results we recommend using a heat gu