These work great, as long you heat longer enough for solder strip to fully meltLove them

These work well and this set has a practical assortment of sizes for general needs around the house, garage, and shop. Plus, it comes at a competitive price. They worked well for me on both solid and twisted 20ga wire, using either a heat gun or a lighter, making extremely strong connections. If you're not familiar with this type of "self-soldering" connector, I recommend viewing a video or reading up on the proper way to use them, which is to twist the two wires together before sliding this over them. Also, it pays to practice first, to get the hang of how fast or slowly these melt. I do much prefer these to crimping connectors.

On occasions when I have to make wire splices, I have a procedure of either using crimped butt connectors, or I just solder the wires together, in both instances using heat-shrink tubing to insulate and seal the connection.I had no idea this kind of combination solder/heat-shrink connector even existed before I stumbled across the listing here. These appeared that they would be far easier and quicker to use compared to my previous method, and are very reasonably priced, so I decided to give them a try. My initial usage for these will be to repair a (low voltage) pool valve actuator wire that was cut by an animal. But before I did that, I wanted to test out the connectors to be sure they worked as expected (including a possible descriptive test of forcefully trying to pull the connected wire segments apart, which I don’t want to do to the real wires), so I tried them on a couple of scrap pieces of 16AWG wire.Although the instructions say to use a heat gun, I also wanted to try using a torch. So I did two test connections, one with a small butane-powered heat gun (no open flame), and the other with a butane mini torch. Both worked fine, but not surprisingly, the torch completed the job much faster. However, as you can see in the final photo, I did scorch the wire’s insulation a bit (though the heat-shrink plastic of the connector itself seemed quite resilient to melting or scorching from the flame).Also, note that in the top connector, some solder squeezed out and made it to the end of the connector. In actuality, this “leak” extended a bit past the end (I picked it off afterward). But this would represent a possible short-circuit issue, because if an adjacent wire that had also been repaired in a similar way also had this kind of leak, they could come into contact with each other and conduct between the two wires. I realized I had concentrated on the center of the connector at first, fully melting the solder before moving on to shrinking the rest of it. What I did for the second one is shrink the ends first (to seal tight against the wire insulation), so that when I melted the solder, it did not have a path to leak out of.Finally, once the connections had cooled, I tried to pull them apart. Despite applying as much force as I could, I was not able to pull them apart. As long as you thoroughly melt the solder, the connection will be solid.A few other notes. First, be sure to position the box with the back (blank) side of the label facing upward before opening. Also, the instruction photos show the wires just touching tip-to-tip as the connector is slid into position, but (and this is probably pretty obvious) the wires should actually be twisted together first. The text of the instructions does indicate this, but the photo contradicts, just showing the ends of the wires butting up against each other.In short, these work great, are easy to use, and are inexpensive... I will definitely be ordering more!

Great

Didn’t expect much at first but I have to say they’ve held up to constant tension and connections still hold. Definitely would recommend especially for the price.

As others (low star reviews) have pointed out - these are NOT going to give you a solid solder joint... BUT these are fine examples of this kind of solution. The solder will flow. The sealant rings will seal. You will always get a cold joint.The correct way to solder any joint is to never heat the solder, you heat the joint / wires and let them melt the solder. Solder will always flow toward the heat and quite simple a shrink tube will insulate the wires you are trying to solder to and they will never get hot enough to allow solder to wick into the strands giving you a cold joint.That said, these little gems do exactly what I wanted them to - they are an easy solution for soldering the wires in the book nooks my wife likes to build and they are more than good enough for that!However, I'd never use them in a high current / mains voltage application - you shouldn't be soldering those joints anyway - you should crimp them.

Excellent I use this on my harbor freight trailer to run my lights and these buds worked really good

Not very impressed with these. It isn't this particular brand either - all the 'heat/melt' connectors I've tried are underwhelming. They're fussy to line up with the stripped wire ends and they never melt very well (have tried heat guns, lighters, small butane torch, etc). When you finally do get it to work, it's not that secure of a connection. They come apart with about 5lbs of pulling force. I'll stick with my Ancor heat shrink crimp connectors. More money, but they're rugged and easy to secure.