Enjoy the dazzling design, sturdy build, brilliant colors and the amazing vapor production from the BDC coil this Maxi offers. BDCs are a major upgrade to single coils because you get both dual coils and a newly designed replaceable coil and airflow system. This unit was designed to eliminate common problems with BCCs such as gurgling, leaking and an airy draw; giving you a perfect, pure taste. These are compatible with 510 drip tips! This holds approximately 1.5ml of e-liquid.