Some of these clips are an open circuit. Of the ones that do work, they only work if you're careful, they're hard to clip on compared to other alligator clips I've used. The reason is that they are poorly designed in my opinion. When you squeeze the lever they rotate inside the insulating jacket (rather than opening). The jacket isn't narrow enough and or the clips themselves are too narrow. My 8 year old son was unable to use these. Others here mentioned that the jacket/boot is too slippery and that's part of the issue too. If you pull off the jacket and clip them, the clips themselves are so narrow that they just rotate between your fingers rather than opening. Maybe tiny, strong and skilled fingers can use these but my fingers would have to develop a new skillset to use them and definitely a child under 10 years old couldn't use them. Overall, this really slows down clipping things on/off and defeats the purpose of using these. Also, the wire gauge is low so I wouldn't expect them to be used for anything over 100mA without the heating issues mentioned. I don't have an accurate measurement but I estimate that the resistance in one of these is between 0.5 and 1 ohms so at 100mA you can expect up to 100mV and 10mW drop in just one. If you cranked that up to say 1Amp you'd be looking at 1V drop and 1Watt which is a heating element (hmmm....maybe Elenco could market these as low cost heaters).These little clip leads are just the ticket for testing small electronics.The alligator clips are about an inch long or so, and the cables are about a foot. The clips are small enough to hook on smaller wires and grip well, and the insulation comes nearly all the way to the tip so you don't cause any shorts.The wires are flexible, so the clips don't pop off while you're working on something. I've had that happen before, where the wires are so stiff, they pull the clip off every time you move your meter. Not these.As the picture shows, you get two of each color: red, black, yellow, green, and white. The different colors are handy for keeping track of which wire is which when you're testing multiple things at the same time.All in all, if you need some test leads, these do the trick.With modern components, it is hard to come up with any good reason to keep alligator clips around the lab. But for whatever reason, they seem to enjoy routine use for quick hookup of power, etc when prototyping. The Elenco isn't the overall best example of alligator clips that I have - certainly I've paid much more money for very high quality clips with heavier gauge while, and stronger jaw springs. But I keep buying the Elenco since the price is great, and they do work quite well. If I recall correctly, I have at least 5 sets of this model. Take that as a recommendation - price is right, they hold up, and I like them enough to keep buying them!I purchased a set of alligator test leads from Radio Shack a few decades ago and they have slowly migrated to the trash bin. These Elenco TL-6 test leads are thicker (3/32" vs 1/16") and less flexible. The insulation is crimped at the end of the clip and the wire is soldered in place. They are 14" end-to-end and open about 1/4". Handy item to have around for testing things especially if you don't have five hands. Quality is better than Radio Shack.Really bad from a usability standpoint, but built fairly well as clips. The problem is that when the clips are squeezed, the clip inside rotates sideways on the slick plastic. It only took about ten minutes before I cut all the insulation of the clips themselves making usable but uninsulated jumper cables.First of all, when I bought these a week ago they said Elenco but now they say they're made by LyonsBlue so I have no idea what's going on with that. I actually have no idea who made the ones I received because they came in a plain plastic bag with no label. The bag was torn at the top so it's possible there was a label and it got ripped off before shipping but who knows.As to the product itself, I'm disappointed. The ends are very slippery and the jaws are very tight which in combination make them difficult to open. There's no writing on the wires themselves so I'm not sure about wire gauge. The wires appear to be crimped on, not soldered. The worst thing though is that the resistance of these wires seem really high to me. I tested several of them and kept getting readings of between 0.6 and 0.9 ohms. My probes at the time were measuring between 0 and 0.1 ohms and were not RELed out, but even subtracting 0.1 ohms still leaves too much resistance for such a short wire. This is all IMO of course, and I don't have a huge amount of electronics experience so if I'm wrong about that being too much resistance I'm sure someone will let me know.For quick desktop prototyping, these clips are great, although I had to drop a star rating because the end sheath over the metal clip slips around when you try to squeeze them.These are alligator clips. They either work, or they don't. These do. Took quite a while for them to arrive......several weeks, and were shipped directly from Asia.