In fact, the Winder 2 has a whole lot of full-fledged motor drive sophistication. It takes bulk film with the 250 Film Back 1, permits wired or wireless remote control, and even provides a seperate M.6V Power Pack 1 for use in extreme cold conditions. Weight is a mere 10.2 oz. without batteries. The usual power source is four "AA" batteries, loaded in the "snap-in" type M.6V Battery Holder 1.