The Switronix Powerbase-70 Battery Pack for Panasonic GH3 / GH4 is a 77Wh 14.8V lithium-ion battery pack. The battery will greatly extend the runtime of the Panasonic G3/G4 when compared to the camera's OEM battery.
It features a 12" DC cable extending from it for convenient connection to the camera and it mounts onto the camera by attaching to its underside, thus doubling as a grip. It can alternatively be attached to a support rig by a 1/4"-20 release plate or by V-mount. 1/4"-20 mounting points are also found on the sides for additional accessories to be attached.