I just went and got a bunch of 808 carto's and an adapter for my 510's, but I have another set of e cigs that seem to be unfamiliar to the folks I talked to at the shop. They are Crown 7's and their carto's are a bit pricey, $20 for 5 plus tax. I am looking to find out if they have the same thread as another battery, and if so, if there is an adapter out to make it take either 510 or 808 carto's. Thx!