Kuject Heat Shrink Solder Seal Wire Connectors Kit 120PCS, Waterproof Butt Connector Heat Shrink Electrical Terminals, Insulated Solderless Wiring Splice Connectors for Marine Automotive Boat Truck

I picked up the Kuject Solder Seal Heat Shrink Butt Connectors for some wiring projects, and honestly, they’ve made my life way easier. If you’ve ever struggled with messy connections or worrying about durability, these will be your new best friend. The best part? The solder ring inside melts perfectly when heated, creating a strong, clean connection without needing extra tools or messy soldering. Plus, the heat shrink sleeve seals everything tight and waterproof, which gives me confidence that my connections won’t fail even in tough conditions. I tested these on my car’s wiring and some home electronics, and every joint has held up great — no corrosion, no loosening, just solid connections. They’re also super easy to use, even if you’re not a pro. With 200 pieces, I have plenty to keep me stocked for future projects. Overall, I’m really happy with the quality and performance of these connectors — they definitely take the headache out of wiring jobs.

I used them on a wheelchair crane project, and they worked as advertised, they shrank formed a good bind and contact. For the price I cannot complain.

Great for putting wires back together in my truck. Easy to use and holds great if you install them correctly. Nice storage included and the quality is good.

Pretty good product, satisfied purchase for sure. I know it’s meant for a heat gun and to solder wires together, but I did neither and it still performs pretty well. I used it as substitution to a slide connector onto a speaker terminal and it works great.

These work great, best idea someone came up with. 5 stars.

So, I actually ordered these by accident, but after I realized my mistake, I figured I would give them a try. I thought I bought crimp and seal connectors like I always use, but these are a low temp solder that melts with a standard heat gun. I used them last night on a replacement headlight connector in a Silverado and they worked like a charm. Cut the old connector off, installed the solder connection and the new pigtail, mate wires and slide the connector and hit it with a heat gun until the solder melts. EASY. I had my doubts at first because I figured the connector would melt before the solder made a real connection, but they worked like a charm. The connector shrunk nicely around the wire and the colored sealant melted into place and spread out and shortly after, the solder flowed into the wires. pretty slick to be honest. the joint set up and seems to be watertight and a solid connection. good value and I'll be using these more often for sure. They seem to be well made and look like the connection will hold up.

TL;DR - the auto shop wanted $1600 for parts and labor. Between these, some parts, and a heat gun, my car runs better than it has in a couple years. Backstory: I have a 2013 Hyundai Veloster Turbo and the last couple of years coils and spark plugs have been going pretty fast. I figured it was something with the ignition wiring or something else electric. The shop I've used regularly quoted me $1600 for new spark plugs, coils, and a wiring harness (all they would use were coils direct from Hyundai for $970!) plus labor. For a 12 year old car that's worth less than $3k I said no way, especially giving Hyundai that much for parts. I bought these guys, a set of coils and spark plugs from Amazon, a heat gun, wire cutter, and electrical cloth tape for about $70. With the heat gun, they worked great. The solder doesn't melt quite how you'd expect, but it does turn into a softer blob and may leak slightly silver - takes a minute or two after you focus the heat there with a narrow nozzle. Make sure the wires are good and jammed or twisted in the middle of the sleeve! I made the mistake initially of not having them touching too well before using the connector and had to redo - luckily they come off fairly easily with heat and wire stripper if needed. All in all, very pleased and having zero issues so far! They shrunk well, connections are solid, and I know the wires will be better protected from humidity and heat.

These work great.. But.... You have to get the heat just right in order for the solder to melt. The big issue is they can not be used in direct sunlight. The covering will totally disintegrate in a month or so (se pic).... If used outdoors they need to be wrapped in tape or covered with a UV resistant shrink wrap.