Neewer Professional Battery Grip(Replacement for BG-E2N) for Canon EOS 20D/30D/40D/50D D-SLR Pro Battery Grip for Canon EOS 20D 30D 40D 50D Vertical shutter with half-press function.Doubling the battery capacity of your camera, effectively extend your shooting time Professional edition with functional buttons.Same function as original Canon battery grip BG-E2N More comfortable vertical shooting Hold 6 AA batteries or 2 BP-511A Li-ion batteries