This is a 2 piece model.You will have a battery and a disposable cartomizer or replaceable clearomizer. Very easy to use. Combine the best mass produced e-cigarette batteries with a disposable atomizer and cartridge combined and you have the KR808D-1. The stock battery for the device has over 50% more capacity than most standard e-cigs stock configuration; the auto version has a very reliable pressure switch and the manual version gives you full control. Initially, the cartomizer was designed to be thrown away after one using but users are finding they can be refilled up to 6 times. The cartridge and atomizer are combined in to one unit that can be refilled but this does require a bit of expertise as it is not as straight forward as refilling a clearomizer. Overall, a very easy, dependable device that is ideal for new users or users not wanting too much fuss with atomizers and cartridges. Long term running without refilling the cartridges will be more expensive than some of the other devices but still less than traditional smoking. Highly recommended.