1High Performance: Three sound effects, duck, patrol and ambulance options, with 12V 120 dB tweeter, loud voice can hear far away. 2High Decibel Alarm: Professional alarm horn, real time decibel value of 120DB, high volume and could keep the sound smooth and not harsh. 3Firm Frame: The bottom adopts metal retention mechanism, triangular screw fixation, easy and firm installation, will not be shaken due to road bumps! 4Waterproof: Light and convenient, rainproof and dustproof, plastic shell, not easy to break, can be used normally even in bad weather conditions. 5Wide Application: The sound quality is clear and loud, energy saving and low consumption, widely suitable for 12V models in a wide range of scenarios.