Must have for Kanger Protanks!
I go through my coils in a week or less usually, just because I don't like letting it get caked on until the gunk flows out and contaminates the liquid.
Also fyi, you can rebuild these with new/custom resistances if you're into that kinda thing. Look it up on youtube for an easy how-to video.
Reviewed by: (Verified Buyer) Layne F. from Hawaii on 9/4/2013