Relay switches for you to plug and run: Lights, Fans, Heater or any other timed device. Each relay is rated to switch 15-amps. 120 Volt AC or 240 Volt AC: USA. 240v, 2-pole relay switches available. Heavy Duty 3 phase 32-amp per phase type available. Relays can be daisy chained with 4-way multi connectors to permit up to 6 relay switches to be switched ON by a single Harvest-Master® output signal (for up to 6 light arrays for example). NOTE: A maximum of 7 relay switches per controller output.