Features: Adopting highly sensitivity deployment probes, with highly sensitivity. Usings microcomputer technology, highly sensitivity, safe and sturdys. After sealing processing, it have a good waterproofs effect. (Note: It can prevent rain but cannot be soak in water for long terms). Easily to install, directly stucks to the screw set of frame, easily to disassemble, more convenience to use. Usage: Press the redness button to set defense and beeps; Pressings the gray button to cancel antitheft will beeps twice. Specifications: Material: Plastic Size: about 10x6x3.7cm/3.94x2.36x1.46inch Power Supply: 9V Battery (not included) Sound: ≤110dB Working current: ＜100mA Package Includes: 1set Wireless Remotes Control Bicycles Alarm note: Please allow 1-2cm errors due to manual measurement, make surely that you not mind before order. Due to difference between different monitors, the picture may not reflect the actual color.