Buy from Amazon.com : http://fave.co/1CcFKOt
Meike Professional Battery Grip Holder Pack Vertical for Sony A900 A850 Replace Sony VG-C90AM
Product Description :
Effectively extending your shooting time
Doubling the battery capacity of your camera effectively extend your shooting time
The battery grip is coated with special material for waterproof splashed water and dustproof
Two stage vertical shutter with half-press function for comfortable vertical shooting
Li-ion battery of NP-FM500 can be used in this battery grip