Features: 1. Support loading MP3 audio format playback, beautiful sound quality. 2. The maximum output of audio can reach 20W, the alarm loudness can reach 110db, and the sound is loud. 3. Built-in SPI memory, support 4Mbit~64Mbit storage capacity, speech length up to more than 2000 seconds. 4. The alarm sound can be directly replaced by usb flash drive. 5. Alarm sound can be selected by infrared remote control, volume can be adjusted (≤ effective distance of 5 meters). 6.Integrated alarm lights and signals -- easy installation 7. Product circuit technology - waterproof, dustproof.