30W40W Stereo Bluetooth Power Amplifier Plate 12V24V High Power Module With Acrylic Shell 1. Stereo audio, wide frequency response, high efficiency, low distortion and low noise, good sound effect 2. There is a volume adjuster, easy to adjust the sound 3. With power reverse connection protection, short circuit protection and overheat protection 4. Wide supply voltage and two input modes, higher efficiency 5. Material: PCB circuit board 6. Power supply voltage: DC 5-24V 7. Bluetooth version: 5.0 8. 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 ohms 11. Adapter speaker (40-200W): 4 ohms (5-16V power supply), 8 ohms (5-24V power supply) 12. Module protection mechanism: power reverse connectionshort circuitself-recovery overheating protection 13. Size: about 5.08x3.8x1.815cm Precautions: 1. Keep a safe distance from the router to avoid wifi interference 2. It is recommended to use 5-24V DC power supply voltage, higher than 26V chip will burn 3. The power supply should be within 16V when connected to a 4-ohm speaker, and within 24V when connected to an 8-ohm speaker 4. The power supply current is recommended to be more than 2A 5. The speaker cable should not be too long, it is recommended to be within 1m 6. 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 burned