Bluetooth 50Amplifier Sound Card 30W with USB Cable Bluetooth 50Amplifier Sound Card 30W with USB Cable 1. This amplifier board requires a 12-24V 3A DC regulated switching power adapter for power supply (tested with batteries, chargers, transformers, and AC switching power adapters; results are not guaranteed for normal operation). 2. Using a 24V 3A power supply, the output power can reach 30W (8 ohms continuous power)! It can connect to a 30W subwoofer + 10W tweeter (4-ohm speaker has protection function) (full volume protection function also exists). 3. After testing, you can connect a battery for power upon receiving the product (do not use 24V batteries, as the voltage of a fully charged battery may exceed 25V, while the capacitors on the board are 25V, posing an explosion risk!). 4. 24V batteries cannot be connected to large trucks, as the charging voltage can reach 28-32V when a truck is on fire, which could cause the truck to burn! Maximum power per channel: 30W Model: Bluetooth 5.0 Amplifier Board Channel: Mono Amplifier Board Color: Green Material: Plastic Package Contents: 1 x Amplifier Board 1 x USB Cable The above only includes the package contents and does not include other products. Note: Light and different monitors may cause the color of the product in the picture to be slightly different from the actual product. The measurement tolerance is +/- 1-3 cm.