[Three-wire input and output] - Heavy-duty timer switch with three-wire input and output, which solves the problem that some customers cannot wire the neutral wire. The maximum power reaches 4KW, which avoids the connection of the contactor. [Versatile Application] - This programmable time delay relay is widely used in 350V-420V AC three-phase motors and other equipment such as water pumps, water oxygenation, etc., fish pond, rice cooker, water heater, display board, neon light, fan. [Weekly Relay] - Easily set the ON/OFF time, with a total of 17 ON/OFF settings. From Monday to Sunday, each setting can be set at least one minute intervals, and the maximum duration is 168 hours (1 week), which can be manually turned on and off temporarily. Once set, it can be continuously cyclically turned on. [Widely Applications] - This programmable time delay relay is widely used in 350V-420V AC motors and other equipment such as water pumps, fish pond oxygenators, rice cookers, water heaters, display boards, neon lights and fans. [Three-wire input and output] - High performance timer switch, three-wire input and output, which solves the problem that some customers cannot connect the neutral wire. The maximum power reaches 4KW, avoiding the connection of the contactor.