Can use the computer USB port 5V power supply or using a mobile phone charger USB port 5V power supply,battery power can also be used
High efficiency:90%,can provide 3W (left channel) +3 W (right channel) output power in the 4Ω load and 5V power supply conditions
A class, B class amplifier such efficiency is only about 30%,D class amplifier is highly respected today
D class amplifier efficiency is extremely high, not because of temperature affect the sound quality but do not add heat sink and take less space

Application:
LCD TVs, monitors,
Laptop
Portable Speakers
Portable DVD players, game consoles
Phone / speakerphone