I'll admit, before I took the trip down the battery rabbit hole, I had already purchased several batteries in preparation for my "stocking". Luckily, I'd only purchased 6 Efest, a couple pair of Hohm Techs, and a couple pair of Golisis which all ended up being okay on Mooch's review list. I will further admit that none of my 18650's fit into my Gen 3 Dual Reuleaux I got not long ago, so I scanned almost the entire list of Mooch's reviews to find batteries that had a tighter tolerance in diameter measurements and ended up with some Imrens. I know, I know, shame shame. All batteries have checked out performance wise though, so I'm going to thank my lucky stars on that.