The Phottix Premium Series BG-A77 Battery Grip for Sony A77 DSLRs feature AEL, AF Points and Exposure compensation button, command dial, vertical shutter button and a power switch. The BG-A77 holds 1 or 2 NP-FM500H batteries and also tripod socket. It also provides a comfortable vertical shooting position due to the additional shutter release button and scroll wheel for easy access to these functions while used in a vertical orientation.