Satter sound in the car. Upgrading the factory sound system to another level is that simple: The Renkforce RF-CMP-204 offers four speaker outputs with 50 watts each and features low and high-level compatible inputs for connecting to the existing source. The amplifier, housed in a robust aluminum casing, can also be used for direct music playback via USB stick or Bluetooth V4.2. Treble and bass controls, along with a volume control, allow for customization to your personal sound preferences. Additionally, there are buttons for play/pause and track forward/backward to control music playback from the USB drive. Special features: Bluetooth and USB audio playback, volume, bass, and treble adjustment.