SureFire Stove Sentry 512 (H512 for Harmon Pellet Stove) Instant Automatic Power Transfer; Battery Cables Included; 2 Year Warranty SureFire 512 interfaces between a wood pellet stove or coal stoker and the AC electrical supply The Surefire 512 can be mounted vertically or horizontally on a flat smooth surface - wall or floor Requires deep cycle, sealed and maintenance free type battery such as a marine battery H512- Harmon Stoves use this model.