The PLSX is an awesome small Pack with settings at 6ws, 12ws 25ws and 50ws. This is a super small and fast solution for photographers who need less power than they used to use but still want the quality of light that Lumedyne is famous for.
This Pack is not modular but has a built in Lithium LiFePo4 battery inside of it. At full 50ws it provides at least 1000 flashes per charge and recharges in just over an hour. It gives many times more flashes at the lower power settings.