I have built an awesome coil! Want to post pics but can't get a good one. Wondering if anyone has already laid claim to the build? It is 2 coils one inside of the other with cotton wick placed between. 28 gauge kanthal micro 7 wraps around small safety pin then 5 wraps around a small screw driver. Slide little coil through bigger coil install on rda. Adjust spacing between coils and then if that was not already a pain get your wicking material between the 2 coils. Sorry I am not to specific on size just use what I have. Comes out to .5 ohm. Good flavor and vapor production.