Apparently the tobeco coils are the best. I use the dual coil 0.3 melo 2 coils in mine at the moment (waiting on tobeco's), i have found that gives better flavor than the 0.5's. You can also use the vaporesso ceramics but i found them too easy to dry hit on a long draw. There are also some new eleaf EC-ceramics coming out. And there is a melo 2 clapton coil that fits as well. Aside from all that they also fit Atlantis and Triton coils I think.