This is the clear cartomizer MT3S from Kangertech. It is an upgraded version of the Kanger MT3S Modular design. This unit is complete with a tube, base and coil but the base has two pieces a metal base as well as a coil unit. This means that the coils can be replaced and it is therefore much cheaper than having to replace the whole of the base. The clearomizer has bottom coils and can hold up to 3ml of liquid. It has graduations marked on the side of the tank and so you can see how full it is when filling and how much is left when you are using it. It is really easy to fill, by unscrewing the base and turning it over. The mouthpiece has also been improved to be more comfortable as it is made of acrylic. It is fixed and cannot be replaced so that the unit does not leak when you turn it over to refill the e-liquid.