As a retired automotive repair technician, I am pretty anal when it comes to electrical repairs. I believe in doing it ONCE for the lifetime of the wire being repaired. The only way to ensure this is to provide a WATERPROOF connection. This shrink tubing is exactly the same as the tubing I used professionally. It shrinks tight and seals with the hot glue that lines the inside of the tube. It also remains somewhat flexible after cooling - a quality I look for because cheap tubing will cool hard and brittle, and will crack open if any sideways force is applied to it.