digital amplifier has below advantages:
with line in function
with charge display
power supply:DC+5V,3.7V optional

digital  amplifier description:

1. Functions:

USB power supply
with line in  function
with charge display
power supply:DC+5V,3.7V optional
output:2x3W

2. Parameters:

power supply:5V;3.7V
valtage: 2*3W
frequency response:10-20000(HZ)
S/N:80(Db)

3. Packaging:

packing:1260pcs/Carton
Carton size:48cm*31.5cm*30cm
CMB/CTN:0.0454m³