Disappointingly bad. I wasted many of these trying to get one good connection, and not one worked properly. I tried a variable heat gun and a butane pocket torch, on multiple settings. No luck. I tried heating very slowly, only on the solder, solder first, then sleeve, sleeve first then solder, no luck. In every case, the heat required to melt the solder was way more than it took to melt and destroy the shrink sleeve.In fact, on most of my attempts, I watched the sleeve just drip away and leave the unmelted solder behind. If I tried to be very careful and only apply heat to the solder band, the plastic would melt off of it and leave behind an almost intact solder ring.I gave up, and switched to normal solder methods, followed by a 3:1 heat shrink tube over it. Much faster, and no mess.