1. Mechanical design: The mechanical clockwork design makes it work without batteries, which is environmentally friendly and can work for a longer time. When in use, please wind it to above 55, and then wind it to the time you want to set. Otherwise itwon't ring or last. 2. Magnet design: There are magnets on the back, which can absorb iron-containing objects such as refrigerators and microwave ovens. 3. Indicator design: There is a green indicator area on the dial, which is easier to identify even if the pointer moves far away. 4. 72 DB reminder design: suitable for a variety of scenarios. Recommended for use in the room you are in. All mechanical timers cannot adjust the volume. 5 Size: 7.3*3.6cm