340PCS Heat Shrink Butt Connectors, Marine Grade Electrical Wire Connectors

A great deal for a complete selection of sizes with large quantities of each. The work as expected, and indeed the tinned copper barrel appears seamless which helps to make the crimped connection robust. I used it with the A1 die on a ratcheting crimper which is specifically designed for heat shrink butt joint crimp connectors. I'm assuming that they didn't want to pay for a higher voltage certification with their mass market being low voltage environmentally exposed systems for automotive, marine, etc. While the heat shrink insulation appears to be the same materials as what you see on 600V certified heat shrink crimp connectors, one can't be certain so I put on an additional layer of 600V-rated heat shrink extending beyond the heat shrink sections of the butt joint just in case for my HVAC wiring application. As others have noted, the heat shrink requires more thorough heating than most, even other dual wall products, but you can see when it has sealed through the transparent insulation.

Good price

Just used some of these for the first time. I had to do a pair of wire splices inside the crankcase cover of a Yamaha Vstar 650 while it was still attached to the bikes electrical system by a bundle of wires running up through the frame!! Two tiny 22-gauge wires (ground & power) from a new pick-up coil to the ignition ignitor that I was splicing into the existing wires in that bundle. I've got big hands working in a small 2-3" space and I used 2 heat-shrink butt splices to do it. These have the solder that melts under a heat gun, and I've never tried these before, but I wanted a tight water and oil proof connection. They worked PERFECTLY and each splice took no more than 1-2 minutes and maybe 20 seconds with a heat gun. No crimping needed, 110 pieces of different sizes all color coded, excellent value if you do a lot of this type of splice and look to be capable of lasting the life of the pick-up coil.

I have read other reviews that have said the same thing and it is very true. This is not like heat shrink tube. This is thicker and is really easy to screw up if you use a propane, torch, etc. Works just fine as long as you use a heat gun. That is more controllable than.

Work as they should. Use the connectors mostly for automotive and recreational vehicle accessory installs and they appear to be holding up well. I think the connectors are waterproof enough for my use as they get splashed by water and rain but they aren’t submerged.

Done the right way, using the proper crimping tool and a heat gun (not fire). There's a lot of ways to connect automotive wiring , some are good, some are bad and some are just stupid. Short of fancier, more skilled and time consuming ways to connect automotive wiring, IMO these are the best things availible on the market. They're waterproof, consistant, easy to use and they better than those 'low temp solder in the middle' connectors which, trust me, will melt together and fail in high heat situations. I've used these type connectors for a long time and will continue using them until something better comes along which I haven't seen yet.

Very well

I have worked in the automotive industry for over 25 years, installing and ultimately designing aftermarket electrical systems and harnesses. I typically use either 3M or Molex, but these compare and are much less expensive. You could go to your local hardware store and pay 10-20 times what these cost. Very good butt connectors. The barrels are sturdy and the heat shrink is tough. Just use a good crimper and you will see good results. A small, butane torch works best for the heat shrink. Hopefully the quality will continue. Really good buy.

Really impressed with the variety in this kit. The heat shrink seals tight and the connectors grab firmly without slipping. I used these for a couple small engine wiring repairs and for trailer wiring — no issues at all. For the price, this is one of the better connector kits I’ve bought.

Work perfectly at a fraction of the cost of buying in stores.

These are the best, they work great seal the connection really well, this all I use now, no complaints

Great kit for the price. Would be better if there was more of the small clear connectors included

Good quality. They work tight once pinched right. Be sure to use a heat gun if you have it - a lighter can work in a pinch but it blackens everything with a risk of burning.