Features:

Can be powered with a computer USB port, USB power bank or a mobile phone charger to supply the 5V support power
Battery power can also be used
High efficiency: 90%
Provides 5W (left channel) + 5W (right channel) output power at 10% THD+N into a 2Ω speaker load and 5V power supply, 3W into 4Ω and 2W into 8Ω 
CMOS class D amplifier design for high efficiency and low cost
Integrated volume controls for left and right channels
Module has short-circuit current and over-temperature protection

Specifications:

Operating voltage: 2.5V-5.5V, recommended 5V
Speaker Load: 2-8 Ohms
Input and Output Connectors: Pins on 0.2" centers
Size: 24 x 23 x 105 mm (L x W x H)
Net weight: 3g

Package Contents:

1 x PAM8406 5W+5W Class D Stereo Audio Power Amplifier Module with Volume Control Potentiometers