1. The supply of the amplifier board requiresDC 12-24V 3A regulated switching supply (the battery and charger, transformer and AC switching supply cannot be used for testing) 2. DC12V 3A (above) supply, the maximum output is 2*15W /8 ohms (full volume may be distorted after turning on) 3. DC24V 3A supply, the output can reach up to 2*26W /8 ohm continuous (4 ohm speakers may be protected) (all volume may be protected) 4. Do not connect to a battery with a standard 24V, because the battery may exceed 25V after being fully charged, and the capacitor on the board is 25V, there is a risk of explosion 5. Do not connect the 24V battery of a truck, because the charging voltage reaches 28-32V when the truck is on fire, and it will burn Product name: Bluetooth 5.0 amplifier Bluetooth version: JL-AC6925A-5.0 supply voltage: DC12-24V Supply current: 3-5A Output : 26Wx2/ 8 ohm Output impedance: 8 ohms Colour: green Material: plastic Size: 96 x 48mm Package Contents: 1 x Amplifier Board Note: There is no manual, please confirm the knowledge of Bluetooth USB circuit board connection before placing an order. Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.