I generally stay away from any 18650s other than the big-name brands. I made an exception here because Mooch, the online battery maven, said these were decent batteries with honest specs. They arrived in good shape in a plastic case. They gave me decent vape time. Ignore the 40A maximum and use them as 20A CDR batteries, for higher Ohm use in a single battery, REGULATED mod or high to mid-range with dual batteries.