Review on 100 Pcs Solder Seal Heat Shrink Butt Connectors, Waterproof And Insulated Electrical Wire Terminals Splice By TICONN by Alvin Bonifacio

I use these wire fasteners frequently for all manner of projects and they generally work well. I fully overlap the stripped wires in the middle of the tube under the center "melt ring" and give the center melt ring a light tap with a small jewelers hammer so the wires don't move. I've had the wires separate with slight movements, hence the hammer tap.I use a heat gun to melt the metal inside to fuse the wires but you need to use care and watch closely. The proper heat both melts the metal fusing ring and the outer plastic sleeve at the same time. Too much heat causes the outer sleeve to melt and not enough heat won't allow the metal solder rings to melt and fuse the wires. It takes a bit of practice. But when you get than hang of these fasteners, they work great.