Notice:1. Please ensure that the power supply voltage does not exceed 5.5V, please do not reverse the polarity of ''+'' and ''-'', otherwise the board will be burned out.2. Please allow slight error due to manual measurement. Thanks for your kind understanding.Features:Small digital power amplifier module.2 *3W - Output 3W+3W for high fidelity sound module is made of high-quality material.Strong and to use, ensures a long service life.2Pcs per :Type: PAM8403 Audio Amplifier ModuleWorking voltage: 2.5V-5.5VMaximum output power: 3W x 2 (5V4Ω)Length: Approx. 29 mmWidth: Approx. 20mmThe total height after installation: approximately 16mmWeight: Approx. 9. Package list:2 x PAM8403 Audio Amplifier ModulesNote:Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.