the two that i own and love like crazy are SKU 1861401 , it has a big 5ml tank and all you do is push down the drip tip and it drips juice down to the cotton and SKU 1720800, is more of a normal dripper, you put in about 15 to 20 drips and you should get around ten full lunge hits till you need to drip some more in, check them out and see if you like what you see, on a personal note i use to run twin coils in them but now i use one parallel coil build, yes you will find yourself using more juice but the clouds and taste are through the roof and your batteries last longer.