Vaporesso SKRR Replacement Coil Heads are designed for SKRR Sub Ohm Tank. It has three types optional: QF Strips 0.15ohm coil, QF Meshed 0.2ohm coil and SK CCELL 0.5ohm coil. QF Meshed coil creates intimate contact with the organic wick for rapid and even heating. QF Strips provides rapid, even heating. QF Strips are the longest-lasting. SK CCELL is including Temperature control through the use of SS316 Coils. Also allowing you to vape at higher wattages, with pure and smooth flavors. Each of them will bring you pure flavor and different vaping experience.