The Power Grip is both powerful and versatile. Doubling the amount of shots that these SLR cameras can take on a single charge, the Power Grip also offers the flexibility of a secondary shutter release button for vertical shooting. It retains the tripod mounting thread as well, keeping the important ability to stabilize the camera during critical shoots.
This battery Grip is for Canon Rebel XSi (450D). It holds two LP-E5 batteries and double 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 and add stability to the camera.
In this professional edition, it comes with several functional buttons as the flash above showing. It will be much convenient for use.
I bought it from (link-delight)