The iClear 16 is a top-coil clearomizer with amazing attention to detail. 4 wicks ensure that each of the dual-coils get enough liquid and never dry out and taste bad. The mouthpiece screws on, and has 2 o-rings on the top and a ribbed o-ring on the bottom to reduce leaking. Also, the plastic tube is held in place by grooves to reduce the possibility of the tube coming loose and leaking. This is the most consistent and best-tasting CE4-style clearomizer out there. Holds 1.6mL of e-liquid and produces a ton of vapor!