Features: 5-band EQ preamplifier: adopt 5PCS JRC4558 op amp, each one is responsible for one frequency band and process the audio signal independently. 5-band separate control knob, easily to control and set the freqency range as you like.Bypass design suits more use: with bypass button to turn off EQ preamplification, the audio signal will output from IN to OUT directly without any processing, convenient to enjoy sound.Attractive looking and powerful design: case and PCB panel, knurled knob, all I/O interfaces are gold-plated to the tight connection and transmission of the audio signal and minimizes the loss of the signal.Mini size and powered by DC 5V: compact design easy to carry, convenient to use in most scenarios, no need to bring a separate power supply, very suitable for of most users.Paramters: Audio input: stereo RCA / 3.5mm AUX Audio output: stereo RCA / 3.5mm AUX Input impedance: 50KOutput impedance: 47Frequency response: 5Hz-154kHz: 0.003%@1KHzEQ Bands: 100Hz, 400Hz, 800Hz, 4KHz, 10KHzBypass function: supportWorking voltage: DC 5V (500mA)Power interface: USB (type-C)Material: Plastic + metalcolour: Package Contents: 1 x EQ5 Preamp1 x USB Cable (type-C)4 x mats