The item you purchased is a Pro Meike Battery Grip for Canon EOS 5D Mark II. It can hold 6 AA batteries or two LP-E6 li-ion batteries, doubling the battery capacity of your camera. Vertical shutter release button on the Battery Grip makes shooting with the camera in a vertical position much easier, adding stability to the camera. 

In this professional edition, it comes with several functional buttons as the flash above showing. It will be much convenient while using. It provides additional shutter release, main dial, AE lock/FE lock and AF point selection controls for easier vertical shooting. Having the same function as Canon BG-E6! 

Note: The battery grip BG-E4 for the previous EOS 5D is not compatible with the new EOS 5D Mark II camera. 

Features:

-Large capacity battery grip is powered by two Battery Pack LP-E6, six AA-size/LR6 -batteries or an optional AC Adapter Kit ACK-E6 

-it has the same feature of waterproof and dustproof with the camera 

-Made from sturdy magnesium alloy and has the same degree of weather resistance as the EOS 5D Mark II 

-Compatible with EOS 5D Mark II only 

-This grip uses the same raw material with the camera body 

Package includes: 

Battery Grip for Canon 5D Mark II x1 

User Manual x1 

Original Manufactory Package 

(Not contain batteries)