A Hahnel HC-550D Battery Grip is simply a must have power accessory for every Canon 550D digital SLR owner. With the Hahnel HC-550D, power is doubled through multiple power sources. One or two Li-Ion batteries* or 6 AA Mignon alkaline or rechargeable LP-E8 Ni-MH batteries* can be used. This is especially useful when taking advantage of the camera's movie mode or Live View mode. Built-in power management regulates the power output to the camera for maximum efficiency. The power management detects use of li-ion or AA batteries automatically. The Hahnel HC-550D is also fitted with a vertical shutter release, making shooting with the camera in a vertical position can be just as comfortable as shooting horizontally.* Batteries not included