It is a small digital power amplifier chip, high-definition sound quality highlights the advantages of digital chips Super small Size (30×22×16mm, NOT included the handle of the potentiometer ), light weight, handy and easy to install Flexible power supply: the module can easily run off three AA batteries, a USB Cell phone charger, a rechargeable Cell phone charge pack Top notch potentiometer, easy and smooth to adjust the volume and control the power switch Crisp and Clear sound output, low noise, give you best hearing enjoyment