The BG-S1 Battery Grip for Sony A77, A77 II & A99 II Digital Camera from Vello is a battery grip designed for use specifically with the Sony A77, A77 II, and A99 II (not original version) digital cameras, and accepts one or two NP-FM500H lithium-ion batteries. With two batteries installed, your shooting time is effectively doubled. Moreover, when one battery is drained, it can be removed and recharged while you continue shooting with the other battery.
The design of a battery grip offers a comfortable and secure way in which to hold your DSLR, especially in the vertical position. It will reduce wrist and hand fatigue when shooting vertically for extended periods of time. The BG-S1 has an alternate shutter release button designed for ergonomic access when shooting vertically and anti-slip rubber gripping to further improve handling. In addition, the BG-S1 has an alternate AF start button, smart teleconverter/focus magnifier, Fn/image rotation button, AEL/slow sync/image index button, AF/MF/enlarge button, exposure compensation buttons, a Multi selector and a main dial. It also features a tripod socket, a strap lug for attaching a hand strap to the camera and a convenient internal slot to fit the camera's battery door when the grip is attached. A battery tray is included to house the NP-FM500H batteries within the grip.