Compatible with all current and previous Seiko Ultrak L10 Timer models (sold separately), the Seiko Ultrak L10 Wireless Receiver W/One Button allows users to easily eliminate tangled and confusing wires. This set includes one wireless lane button and one receiver, which are operated by radio frequency and can link up to 10 buttons. Presettable RF channels avoid cross interference with nearby L10s. 100 ft/30 m operating range. User presets lane numbers for each individual button. Battery operated (two AAA batteries for buttons and receiver box, not included).