The Map Tank is a see-through liquid container / feeder compatible with all 510 threaded devices. There are many variations of this device available. The regular tank will hold 5ml’s of juice and the Mega version will hold 12ml’s. Both versions also come with three different resistances to chooce from: 2.4ohm, 2.8ohm and 3.2ohm. Map Tank E2 is made out of delrin / lexan and is re-fillable. You can use a 510/901 driptip as a mouthpiece.