Features: Bicycle Security Enhanced: your bike's with our advanced Bicycle Alarm System. It's equipped with a high-decibel alarm that wireslessly communicates with a remote control, providing robust anti-theft functionality. User-Friendly & Versatile: This alarm system comes with a USB rechargeable battery, eliminating the need for constant battery replacements and promoting eco-friendliness. Its wireless design allows for easy installation without the hassle of wiring. Portable Protection: Compact and , this system is not only limited to bicycles but can also be used for other vehicles, offering broad-spectrum security. Specifications: Host built-in battery: 3.7V 700mAh lithium battery, daily use lasts 1-3 months, continuous standby lasts about 6 months Charging interface: Standard U SB-C5 V (some fast charging heads are not compatible) Remote control battery: WL03C: 1 27A (12V) alkaline battery for daily use for 1-2 years (counting 5 remote controls per day) Waterproof rating: IP65 Waterproof and dustproof Transmission and reception frequency: 433.92MHz Working environment temperature: -40~+70 ° C Working environment humidity: Less than 80% Storage environment temperature: -40~+70 ° C Due to different batches, there may be differences in product appearance and printed text, which will not affect use Material: PC colour: Black Package Contents: 1 x Bicycle Alarm kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.