US users need to buy another voltage transformer(not included here.)Power on delay, plus timing. With large transparent time setting knob for setting time easily, 8 pin solder terminal for installation. Time Delay Relay used i_n industrial automation system and mechanical equipment to delay component. Relay is a kind of automatil electric switch, when supply with an input value, like electric, magnetic, light or thermal signal, it wall transfer the controlled circuit automatically and make an abrupt change, when the input value decreased to certain degtee, it will resume to former state and make the controlled circuti back to the former stare. Features LED indicator show power and output status.