Energizer A544 Battery provides reliable power to your important electronics. This small battery is compatible with a variety of devices, including your bluetooth headset and medical devices. Reach for this alkaline battery when you need a replacement camera battery or a battery for your dog's LED collar. Miniature alkaline batteries contain zero mercury to reduce environmental impact. Count on Energizer, the #1 brand of specialty batteries, to deliver dependable, long lasting power to your devices.