1. The supply of this amplifier board requires 12-24V 3A DC regulated switching supply (testing with battery and charger, transformer and AC switching supply is not guaranteed)2. 24V 3A supply, the output can reach up to 30W 8 ohm continuous It can be connected to 30W + 10W tweeter (4 ohm speaker may be ) (full volume may also be )3. After the test is completed, the battery can be connected to the supply after receiving the goods (the 24V battery is not allowed, because the battery may exceed 25V after being fully charged, and the capacitor on the board is 25V, there is a risk of explosion )4. It is not possible to the 24V battery of a truck, because the charging voltage reaches 28-32V when the truck is on fire, and it will burn Maximum Per Channel: 30W Number: Bluetooth 5.0 Amplifier BoardChannels: Mono Stage Amplifier Boardcolour:GreenMaterial:plasticPackage Contents:1 x Amplifier Board1 x USB lineOnly the above package content, other products are not included.Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-YJL official store