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.

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 things are the bomb. I used them to wire 2 car head units and an alarm system. The water resistant seal seems legit but haven't exactly put it to the test. The solder holds the joint just as it should. After wiring a harness I gave it a nice hard tug to see if the joints pull apart but it held strong. I used flux on the wires tips of second harness I wired because its ensures a better flow onto the wire but it isn't necessary. The first harness is just as solid as the second one with flux. The only gripe I have with these things are when pulling a wire through the connector that was a tight fit, it sometimes pulls the water seal ring out with the wire and it's a bit of a pain trying stuff it back to its place which is about a quarter of the way down. I just ended up just sealing it right at the end of the connector because I was tired of fiddling with the thing. This could cost you time if you let it. Seal them at the end or anywhere in the connector if this happens, it's just as good. I dont have a heat gun at the moment but I have lighter, and it worked just fine. I was curious to see if a hair dryer would work so I gave that a shot but it doesnt get hot enough so dont waste your time. Its makes your work look very clean and professional compared to crimping butt connectors which I'll probably never go back to. I highly recommend these bad boys.

I have all manners of connectors and soldering stuff but these are the best and easiest way I've tried. Solder melts the wires together and the heat shrink seals it from the elements. These also take less space meaning cleaner installs. I won't have to buy any more for a while, but would absolutely buy these again when I run out.

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.

Easy to use and make waterproof and strong connections.

These are the SHIZZZ!, all my life, when making electrical connections i knew by science, soldered connections are the best. This is solder,and heat shrink in one step. And can be completed with a bic lighter.

Worked well when new but after 6 months or so the solder on the remaining ones stopped melting at all. Ended up throwing more than half of them away because they simply stopped reacting to heat.

Nice product. Makes the wiring eaier so no need to solder them this doea it for you. Easy to use with heat gun

So far they work well and do the job. Easy to use. Worth the cost.

value for money

Super handige alles in 1 oplossing om kabels te solderen en isoleren. Scheelt een hoop tijd met dit setje.

Trotz einiger gegenteiliger Meinungen finde ich diese Verbinder äußerst praktisch, besonders für den Außenbereich. Sie bieten eine hervorragende Verbindung mit geringem Widerstand, und der Schrumpfschlauch dichtet perfekt ab. Bei richtiger Anwendung gibt es absolut nichts auszusetzen. Top Produkt!