Mechanical Timer: Large dial with clear scale; quartz movement starts automatically within a few minutes after power-on. Easy to Use: 24-hour timer with manual switch, supports programming time control (automatically turn on/off according to schedule) and permanent on/off. Built-in backup battery. DIN Rail Mounting: Easy to install and disassemble, flexible use. The programmable mechanical timer makes your life smarter and more convenient. Transparent Dust Cover: Dustproof and splash-proof, extends service life. The transparent design does not obstruct the view of the dial. Wide Range of Applications: For street lamps, ventilation, fountains, advertising signs, production equipment, radio and television equipment, etc. For dry indoor use only. Note: 1. Installation should only be carried out by a qualified electrician. 2. Please read the instruction manual carefully before use. 3. Size and color may vary slightly due to manual measurement and different lighting conditions. Thank you