The Sony BC-U2A Dual-Bay Battery Charger AC Adapter is a dual-bay charger that supports the simultaneous charging of two Sony BP-U90, BP-U60, BP-U60T, or BP-U30 Li-ion batteries. It also functions as an AC adapter that can be used to power a camera directly while also charging one battery simultaneously. The AC adapter provides a 12 VDC power output via an integrated cable that can be connected to any Sony camera that accepts BP-U series batteries. A selector switch on the front of the device allows you to switch between charger and AC adapter mode.