The XSMF is a very special High Speed Module that makes the Lumedyne flash system recycle much faster. It plugs between the Extra Large Battery or a few other high power options and Pack or the rest of the system. It creates a much-much faster recycle time at any power setting.
This unit draws so many amps only the Batteries, etc. that have the extra power connections can work with this Speed Module. Any of the eligible Packs may be used and they won't get brighter. They will recycle super fast from those limited power options.