Features： 1、HIGH DECIBEL: The alarm sound can be up to 110 decibels at testing distance of 10cm, which can effectively warn passersby and vehicles. 2、CONTROL DISTANCE: This bike alarm supports remote control, with an open distance of 50‑80 meter, it is recommended to use at 10‑20 meter. 3、BUILT IN BATTERY: Equipped with 500mAh lithium battery, charged for 2‑3 hours, with a standby time of over 30 days, and used for about 15 days. 4、CHARGING INDICATOR: When charging, the red indicator remains on, blue flashes, when fully charged, the red indicator goes out, and blue flashes. 5、MULTIPLE CONTROLS: 1 host can adapt to 5 remote controls, 1 remote control can control multiple hosts at the same time, support multiple users and multi point control. 6、PLASTIC HOUSING: The wireless vibration alarm adopts plastic shell, waterproof and rainproof, with good toughness, can be used in various environments. Specification： Item Type: Electric Vehicle Alarm Material: ABS, Electronic Component Alarm Battery Type: 500mAh Lithium Battery (built in battery) Remote Control Battery Type: 3 x 75mAh CR2032 Button Battery (built in battery) Package List： 1 x Alarm 1 x Remote Control 1 x Charging Cable 2 x Ties 1 x Screwdriver 3 x Screws 1 x Nut 4 x Accessories 1 x User Manual