The performance of a bottom-coil meets the form factor of a carto tank! The Pro Coil is made to replace the cartomizer in your U-DCT V1 or V2 with a design much like our bottom-coils. Large holes and short wicks ensure that your coil will never run dry, nor leak. These are great if you have ever experienced a flooded tank. These coils are not dependent on air pressure, and are extremely resistant to leaking and flooding. They offer copious amounts of vapor and a smoother draw!