They are waterproof and they seal to the wire good and have perfect connection. Just use a heat gun not a torch. Make sure to get a quality Brand heat gun

I used similar connectors in the Airforce doing wiring on F15 fighter jets. The connectors are great for adding a wire to the braided shields too ground them. Good to use for marine applications where water is an issue. The quality is not the best, but good for the price. High quality solder connectors run around $1.00 or more each splice.Pro.1) better than using a crimp type connector2) the adhesive seals great3) makes joining two different diameters of wire easy4) keep some connectors and a lighter in a glove box or tool box on a boat for emergencies.5) not recommended but they can work with a standard bic lighter.6) the diameter is smaller than crimp connectors when used making for nice installationConn.1) the heat shrink will get a hole if your wire isn't setting flat2) not as good as solder and a iron3) the solder joint always looks like a cold solder joint.4) quality is not consistent5) one connector the heat shrink broke open before the solder could melt

I used these during a recent Auto stereo upgrade. These connectors helped to make better connections between the wiring harness and the head unit wiring. They worked well. I just had to be sure to use the right amount of heat to get a good solder connection. No complaints so far. This probably has enough the last me a lifetime.

When your used to doing a splice or connection a certain way for long it takes a little time to trust a new way because the old way worked so well. The first few tries didn't go smooth. But as i made a few more attemps you then get a feel on how to actually make it work right. Inserting the cut ends into the connector doesn't leave much room for error. If either wire slips then the wires won't touch and your left with a useless seal. My work around I cut my wires at a slight angle so when they're inserted into connector the tips slide just past the solder collar on both sides. Apply heat and now I got a solid connection. The shrink wrap helps the keep the wires intact. I gave a good tug and they didn't slide out.