The Canon BG-E8 Battery Grip for the EOS Digital Rebel T2i, T3i, and T4i DSLR cameras holds up to (2) LP-E8 battery packs simultaneously to effectively double your shooting power, plus the grip includes a holder to use (6) AA batteries. In addition, the grip includes a vertical shutter release and a mode wheel to provide access to all of the camera functions and make shooting with the camera in a vertical position just as comfortable as shooting horizontally.

Compatibility

This grip is compatible with several T2i, T3i, and T4i camera bodies and kits, including:
Rebel T2i, EOS Rebel T2i EF-S 18-55IS II Kit, and EOS Rebel T2i EF-S 18-55mm IS Kit

EOS Rebel T3i (body only), EOS Rebel T3i 18-135mm IS Kit, EOS Rebel T3i 18-55mm IS II Kit, and EOS Rebel T3i Body Refurbished

EOS Rebel T4i (body only), EOS Rebel T4i 18-135mm f/3.5-5.6 IS STM Kit, EOS Rebel T4i 18-55mm f/3.5-5.6 IS II Kit, and EOS Rebel T4i Body Refurbished