A clearo uses a screw in wick and coil assembly. A carto gets pushed into a
tank. A clearo generally has a silica wick directly 'floating' in the
tank, whereas a carto has a hole or holes which draw in liquid by suction and gravity, where it saturates polyfill, which surrounds the coil. For me, carto-
tanks are far superior; flavor, ease of use and longevity.