Features 1、20W Mono Channel HiFi Amplifier Board. 2、Made with high quality electronic components, stable and reliable. 3、Using military grade double‑sided circuit board. 4、Reasonable layout, compact size. 5、You can assemble these components by yourself and obtain knowledge about amplifier board. Specification Features: 20W Mono Channel HiFi Amplifier Board. Made with high quality electronic components, stable and reliable. Using military grade double-sided circuit board. Reasonable layout, compact size. You can assemble these components by yourself and obtain knowledge about amplifier board. Specification: Output power: Typical 20W (maximum 30W) Speaker impedance: 4Ω-8Ω Total harmonic distortion: <0.04% SNR: 105dB Frequency response: 14Hz-100kHz (maximum range 3.29Hz-482.29kHz calculated by RC high and low pass circuit) Package list: 1 * Amplifier Board DIY Kit (Require assembly) Package List