Battery is included. Contains: 5 in 1 Remote Control fit for Canon Nikon Sony Pentax Olympus x1 Lithium CR2025 battery (inside) ... . Energy-saving design allows long battery life usage. Good choice for you! It can trigger the camera shutter release remotely from ... , 370Zfor Olympus: E-520, E-510, E-500, E-420, E-410, E-400, E-330, E-300, E-3, E-1. E-30,E-20, E-10, E-100RS, E-2500, E-2100for Pentax:Km ...