1、When the power of the timer switch is not enough, you only need to replace the battery. 2、The timer switch is a programmable timer, set a schedule to control your appliances, and has a backlight. 3、The timer switch can be used for 24‑hour intelligent analogue timing, and it can be set on/off 16 times a day. 4、The long working time of 1 minute to 168 hours, so you don't need to worry about power problems. 5、You can save energy and money, as well as electricity bills. You can use it for lights, ceiling fans, etc. Item Type: Digital Analogue Timer Switch Material: ABS Model: TM928AK Display mode: LCD Backlight Working Voltage: 85-265VAC Load: 16A Power Consumption: <5VA Time Range: 1min-168hrs Power Failure: 90 days Program: 16 Times A Day ON/OFF Average Error: <±2 Seconds/Day Temperature Range: -10-50℃ Humidity: <95% Installation Method: DIN RAIL Features: 1. Clock Display 2. Programmable Timer 3. With Backlight Battery Parameters: Removable Button Battery CR2032 3V 240mAh 1 x Switch 1 x English User Manual