They're just regular 510 atties. I loved them the first time around with vaping- and I'm still using them. I switch back and forth between the Boge 2 ohm cartos. I did try a 306, and some of the Cisco's- but keep going back to my stand-by's. I never figured out the 306's and they burned my juice. The Cisco's aren't a lick better than the XV ones IMHO.
They give a great consistent vape, and I think the flavor is a bit better than the Boge cartos.