Built-in high-quality MP3 player with 8MB flash memory. Supports USB flash drive and micro-SD card for extended storage. Compatible with up to 32GB USB flash drive and up to 32GB micro-SD card. Features 7 trigger inputs that can be connected to push buttons, switches, relays, or similar devices. Equipped with a built-in 50Wx2 Class D amplifier for powerful audio output. Audio files can be uploaded by connecting the device's micro-USB port to a computer using a USB data cable. Volume is adjustable via a rotary knob. Capable of driving external equipment such as warning lights or motors while playing audio. Includes a 3.5mm audio output jack for connection to external amplifiers or active speakers. Housed in a durable aluminum alloy case. Industrial-grade design with strong anti-interference performance. Operating voltage: 12-24V DC Operating current: 8500mA at 12V (with two 50W speakers), 4250mA at 24V (with two 50W speakers) Power consumption: 100W Flash memory size: 8MB Audio format: MP3 8 trigger modes available Model: Negative Trigger Version Color: Black Material: Plastic Package Contents: 1 x 7 Triggers Audio Player Note: Other items not included. Note: Lighting and display differences may cause slight color variations between image and actual product. Measurement tolerance: +/- 1-3 cm.