5x PAM8403 Digital Amplifier Module USB Power Supply 2x 3W Class D High Efficient 2.5-5.5V Mini Power Amplifier Board 
Feature:
1. The working voltage is 2.5V-5.5V. Note: The power supply voltage should not exceed 5.5V, and the positive and negative of power supply should not be reversed.
2. Speaker Configuration: 4-8 ohms, recommended: 4 ohms; speaker power: 2-8W.
3. You can power supply via 5V computer USB port/5V mobile phone charger USB port/lithium battery.
4. High efficiency 90%, 4Ω load and 5V power supply conditions, can provide 3W (left channel) +3W (right channel) output power. The efficiency of class A and class B power amplifiers is only about 30%, and class D power amplifiers are highly regarded in the current trend of green environmental protection.
5. Class D power amplifier has extremely high efficiency, will not affect the sound quality due to temperature rise, and does not need to add a heat sink, which takes up a small space.
6. Built-in noise elimination circuit, and there is no noise when the power is turned on/off; The module has short-circuit, over-current protection and over-temperature protection.

Specification:
Product Size: 21 X 18 X 2mm/0.83 X 0.71 X 0.08"
Application:
1. LCD TV, Monitor
2. Laptop
3. Portable Speakers
4. Portable DVD Player, Game Console
5. Mobile Phone/Hands-Free Phone

Note:
1. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you!
2. Please allow 1-3mm measuring deviation due to manual measurement.