I use AW IMR 14500's in my madvapes 3.7 volt box mod as well as their VV box mod. The IMRs are shorter than Li-ion batteries sold on madvapes' website and fit in the mod better than protected batteries (protected Li-ion batteries fit very tight). I would assume that any IMR would fit better in these mods as the IMRs have no protection circuit and are almost always shorter than protected batteries. IMRs also perform better and are a safer battery chemistry