It's a cheap alternative to the CTB6185, CTB6187 series, but no idea if they are any good,or not. What I can say is the CTB6185 batteries were defective from the start( the electronics in them) and that's why the CTB6187 was introduced, so if you end up going the Snap-On used battery route, stay away from the CTB6185
Also, they're wrong on their CTB4185 and CTB4187 replacement, as they state it. Those batteries are ni-cads. This battery replaces CTB6185 and CTB6187 li-ion batteries, although you can use either on many of the impacts and drills they fit on. The CDR6850 drill and CT4850HO and CT6850 impacts and CTRS6850 saw, for sure they will work on. It's said not on the 4850 series tools, although I've never tried it, don't know why they wouldn't, except for possible differences in the switches ( triggers) the tools used.
