I used these connectors on a fountain project and they are great. The design allows me to crimp all the wires on one side of the cable and then connect the other side one at a time so you don't have to try to connect both sides at the same time. I effectively used a Mapp gas torch to waterproof the connections, but I think a smaller lighter would actually work safer to prevent burning nearby wires. A little PVC cement was applied to the finished product to ensure reliability in underwater applications, but that's probably overkill.