Features 1、Made of flame retardant ABS plastic, sturdy and durable to use. 2、Microcomputer intelligent control and steady performance. 3、Connect 12V power supply, automatic stroboscopic. Need to distinguish between positive and negative, red to positive, black to negative. 4、110dB sound volume, to make sure you can hear the alarm sound at anywhere in your home. 5、Suitable for security guard booths, gates, roads, tunnels, airports, construction sites as warning lights. It can also be used as photoelectric alarm output of alarm host. Specification Features: Red and blue two colors for your selection. Made of flame retardant ABS plastic, sturdy and durable to use. Microcomputer intelligent control and steady performance. Receiving alarm signals, alarm with loud sound and flash. Connect 12V power supply, automatic stroboscopic. Need to distinguish between positive and negative, red to positive, black to negative. Suitable for security guard booths, gates, roads, tunnels, airports, construction sites as warning lights. It can also be used as photoelectric alarm output of alarm host. 110dB sound volume, to make sure you can hear the alarm sound at anywhere in your home. Specifications: Rated Current (mA): 300 Sound pressure (VDC): 110±3 Size: 12.5*7.5*4.5 cm/4.9*3.0*1.8in Package Weight: 118g/4.2oz Package List: 1 * Acousto-optic alarm 2 * Screws