You can use the computer's USB port 5V power supply or a mobile phone charger's USB port 5V power supply.
Battery power can also be used.
High efficiency: 90%
Can provide 3W (left channel) + 3W (right channel) output power in the 4Ω load and 5V power supply conditions.
A-class, B-class amplifier efficiency is only about 30%.
D-class amplifiers are highly regarded today.
D-class amplifier efficiency is extremely high; temperature does not affect the sound quality.
It does not require a heat sink and takes up less space; a noise-cancelling circuit is built into the amplifier board.
Power on/off without pop noise.
The module has short-circuit current protection and over-temperature protection.

Specification:

Operating Voltage: 2.5V ~ 5.5V
Speaker Impedance: 4Ω ~ 8Ω (recommended: 4Ω)
Speaker Power: 2W ~ 8W
Size: 21 x 18 x 3.4mm (L x W x H)
Net Weight: 1g

Application:

LCD TVs, monitors
Laptops
Portable speakers
Portable DVD players, game consoles
Phones/speakerphones

Note:

First turn off and then power on the speakers, or you may damage the chip.
Because the digital volume control module has high gain, do not let the audio input signal exceed the limiter.