Switch function: Supports 16 groups per day on/off, one button automatic, can be set to cycle through day/week. Two-way control design, 3.4 is a normally open switch, 3.5 is a normally closed switch, and 3.4.5 are connected as dual control switches. High-quality materials: This timer relay is made of high-quality durable hard plastic materials, rust-free, anti-corrosion, and high strength for maximum durability. The surface is smooth and burr-free, and the hand feels delicate and comfortable. Manufactured under strict quality control standards, the improved design can extend the service life. Application: The timer switch can automatically turn on and off various types of electrical equipment according to a fixed schedule. Advanced preset one week before, DIN rail installation. This timer relay widely used to control lamp, water heater, sprayer, bottler, preheater, agricultural facility, broadcasting equipment, household appliance, etc. High precision: This timer relay built-in 1.2V / 40mA rechargeable point, high precision, industrial-grade chip, strong anti-jamming, using 8-bit industrial-grade chip, small error, high stability, accurate travel time, daily travel time error is less than 2 seconds. Superior performance: With built-in high-performance batteries as backup power, it can maintain time display and store data for more than 6 months when disconnected from the mains. The time control circuit and the load circuit are separate from each other. The passive output at the output can also be used for signal control.