[USB Rechargeable, No Replacement Required] The digital watch is a rechargeable type, so there is no need to worry about replacing it. There is a USB connector on the dial, so you can use any USB adapter. It can be charged using a mobile phone's charging head or a computer's USB connector. Normally, you can charge it for 1 hour and use it for about 10 to 15 days. [Multi-functional & super comfortable material adopted] The alarm clock adopts vibration mode, so you can set the study alarm in a quiet environment such as a library and it will not affect other people. Alarms can be set at specific times and are useful for regulating break and study time. The vibrating design will not disturb other people, suitable for use in libraries, classrooms, dormitories, etc., and is very suitable for students. The soft strap is comfortable during exercise and daily use, and the band will not snap when dropped. It is more comfortable to wear and can better protect your wrist. Because it is elastic, it is easy to remove the dial and charge it. [Suitable for] Unisex. A Swiss watch that combines individuality and practicality, and a size that can be used by both men and women. In addition, it can be used in a variety of situations, such as work, school, daily life, and exercise, and is suitable for combining different styles of clothing. [Waterproof] Waterproof and can withstand sweat, rain and splashes. You no longer need to wash your hands or take off your watch in daily life. [Product F&Q, video support, warranty, etc.] The delivery period can be guaranteed within 3 to 10 days, and returns and refunds can be accepted within 30 days after receiving the product. If there is an initial defect, please feel free to contact us. We will respond within 24 hours (we can provide instructions using photos and videos via email, Facebook, LINE, and other apps). Contact method: [Account Service] > [Order History] > [Seller] > [Ask a Question].