Those M-Dual coil 0.38ohm, M1+ coil 0.16ohm are perfectly compatible with Horizon Falcon King Tank. The F1 and F2 Horizon Falcon Replacement Coils are both rated 0.2-ohms, and both utilize vertically-oriented parallel coils. The main difference is that the F1 utilizes a liquid guiding element comprised of 70% cotton and 30% wood pulp. On the other hand, the F2 features natural flax fiber. The F3 Falcon Coil runs with 0.2-ohms of resistance and also utilizes vertically-oriented parallel coils. The liquid guiding element comprises of flax fiber and flax paper, making it a great choice for those enthusiasts seeking a different tone and nuance to their draws. the M1 Falcon Coil is rated at 0.15-ohms of resistance, while the M2 coil is rated at 0.16-ohms. Both utilize mesh coils to better facilitate the extraordinary power going through them. The M1 and M2s liquid guiding elements use a 70% cotton and 30% wood-pulp mixture. Brand: Horizon Unit: 3pcs/pack Resistance: M-Dual coil 0.38ohm, M1+ coil 0.16ohm Package: Simple Packing Shipping method:Please check here for details.