The iSub series from Innokin employ a new and innovative technology Innokin are calling the “No spill coil swap” system. Essentially the coil can be removed without the need to ‘open’ the tank. What this means is that the Innokin iSub Replacement Coil houses the 510 connector pin itself, making cleaning the iSub and iSub G Tank a breeze as well as increasing both tanks longevity.