Kanger produces some of the most popular electronic cigarette devices on the market today. Their replacement coils are no different. These Kanger replacement atomizer coils feature Kanger's new Bottom Dual-Coil (BDC) design, resulting in an incredible vaping experience. The Kanger Dual Coil heads not only offer the benefits of a bottom-coil system, but also provide double vapor production due to the dual coils. The upgraded coils from Kangertech come with 4 roles instead of 2 holes. The results are amazing, as many vapers love them along with the BVC coils.