Features:
Operating voltage: 2.5V-5.5V
Maximum output power: 3W*2(5V 4??)
PCB size :
Length: 29mm
Width: 20mm
Overall height after installed is about 16mm.
Note:
please make sure the power supply is not more than 5.5V and please don't do reverse polarity for ""+"" and ""-"", or else, it will burn the board.

Package Included: 
1x PAM8403 3Wx2 5V Dual Channel Power Audio Amplifier Board