Pentax GPS Unit O-GPS1 Hotshoe Mounted Accessory GPS Unit for Pentax K-5, K-r, 645D Geotag your images for location information on popular photo sharing websites Chart the progress of a hike, bike or boating trip with interval position tracking A separate, but efficient power source will not drain your camera's battery Supports terrestrial based WAAS for highly accurate positioning Electronic Compass function assists while hiking or camping