Model: Y148 - PCB board - Adopts YDA148 high-efficiency digital audio power amplifier IC - DC input voltage: 9~15V - Current: 2~4.5A - Power output at DC 15V input: 15W x 2 (8 ohm) 30W x 2 (4 ohm) - Power output at DC 12V input: 10W x 2 (8 ohm) 20W x 2 (4 ohm) - Needs heat sink at 4 ohm doesn't need heat sink at 8 ohm - Frequency response: 10Hz~20KHz(+/-0.2dB @1KHz) - Load speaker: 4 / 6 / 8 ohm - SNR: at least 90dB - Harmonic distortion: THD+NC no more than 0.1%P=0.1W Note: The input labeled R_in is really the left channel and L_in is the right channel pls check it before installation Datasheet: http://m5.img.dxcdn.com/CDDriver/CD/sku.93121.xls