The Vapefly Fantasy Mini coil heads have two options:
M2 – 0.5 ohm double coil head rated for 40-70W
M8 – 0.15 ohm octuple coil head rated for 50-120W (best 60W-80W)
A great feature of both these coil heads is that they can be used in other tanks.
The M2 coil heads are compatible with the Aspire Atlantis, Triton V2, Eleaf Melo 1, 2 and 3, iJust 2, iJust S.
The M8 coil heads are compatible with SMOK TFV8 Baby Beast and Big Baby Beast, Ijoy Exo X and Exo S.