1. Stereo audio, wide frequency response, high efficiency, low distortion and low noise, good sound effect2. There is a volume adjuster, easy to adjust the sound3. With power reverse connection protection, short circuit protection and overheat protection4. Wide supply voltage and two input modes, higher efficiency5. Material: PCB circuit board6. Power supply voltage: DC 5-24V7. Bluetooth version: 5.08. Transmission distance: about 15 meters (visible and unobstructed)9. Number of channels: two channels (stereo)10. Output power: 20Wx2 12V 4 ohms, 30Wx2 16V 4 ohms, 30Wx2 21V 8 ohms, 40Wx2 24V 8 ohms11. Adapter speaker (40-200W): 4 ohms (5-16V power supply), 8 ohms (5-24V power supply)12. Module protection mechanism: power reverse connection/short circuit/self-recovery overheating protection13. Size: about 5.08x3.8x1.815cmPrecautions:1. Keep a safe distance from the router to avoid wifi interference2. It is recommended to use 5-24V DC power supply voltage, higher than 26V chip will burn3. The power supply should be within 16V when connected to a 4-ohm speaker, and within 24V when connected to an 8-ohm speaker4. The power supply current is recommended to be more than 2A5. The speaker cable should not be too long, it is recommended to be within 1m6. Pay attention to electrostatic protection. Before touching the power amplifier board, you need to release the static electricity on your hands to avoid the breakdown of the chip by static electricity. The Bluetooth chip is more sensitive to static electricity.7. It is recommended that the rated power of the speaker is 40W and above to avoid the speaker being overheated and burnedSpecification: Package Weight One Package Weight 0.05kgs / 0.10lb One Package Size 8cm * 6cm * 2.5cm / 3.15inch * 2.36inch * 0.98inch Qty per Carton 500 Carton Weight 27.00kgs / 59.52lb Carton Size 50cm * 50cm * 54cm / 19.69inch * 19.69inch * 21.26inch Loading Container 20GP: 197 cartons * 500 pcs = 98500 pcs40HQ: 458 cartons * 500 pcs = 229000 pcs