Instructions for use: 1. D325D supply voltage is DC24V-48V, the higher the voltage, the higher the power. The voltage can not be higher than 48V, otherwise it burn the machine. 2. DC power supply seat specifications are 5.5 x 2.5, positive and negative. 3. D325D output can only be connected to passive speakers, can not be connected to active speakers and fixed voltage speakers. Model: D325D Input: , AUX 3.5 Output: Small crystal terminal block 2 sets Operating Voltage: DC24V-48V Standby power consumption: 1W Amplifier chip: TPA3255x7 Output power: 300Wx2/40, 150Wx2/80 Total harmonic distortion: Less than0.02% Signal-to-noise ratio: 110DB Frequency Response Range: 20- 20K@1KHZ+0.3DB package: Yes Channels: 2 (2.0) Maximum Power Per Channel: Above 200W Material: Metal colour: Black Package Contents: 1 x Audio Amplifier Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.