HiFi Stereo AMP -- This Dual channel stereo digital amplifier offer 300W+300W power and 40W+40W rated power. Amplifier can input 12-240V. Bluetooth 5.0 -- Built-in bluetooth 5.0 core, no , no audible noise when Bluetooth connection is established, designed for the customers who pursue HiFi sound. (NOTE: Please keep the distance within 30ft/10m between the device and amplifier without any wall blocking. But if you are connecting whith TV or PC devices, please keep the distance within 15ft/5m.) USB 2.0/SD Card Input -- The sound amplifying mixer device features a USB/SD card input to support flash drives or SD card. Allows you to play your favorite audio files from your computer's media library when you connect it directly to the amp. Bass & Treble Control -- Designed with volume, treble and bass control knobs for more delicate adjustment of the sound, much fun and high playability. Include controller for distant audio adjustments. Note: There is an isolation plastic sheet at the bottom