6: Stylish and unique overall design, electronic tubes with VU meter, so that the machine is full of nostalgic retro feeling, small size, easy to desktop placement. 7: INPUT input 4 way left and right channel signal / 2 groups OUTPUT output 2 way, 4 groups of input signals and 2 groups of output signals between isolation, no interference between input and output signals each use at ease, no noise, no crosstalk, gold-plated RCA interface, low resistance and high conduction, rugged and durable. Plug Type:US Plug,it applies to Canada, India,Mexico, Thailand, the , the Philippines, and so on. Voltage:AC100-240V Input signal: 4 way stereo signal Output signal: 2 way stereo signal Frequency response: 20HZ-20KHz Product size: 145 x 85 x 85mm High-bass adjustment range: ±6dB Input sensitivity: 0.775V Harmonic distortion: 0.04% typically Operating voltage: 12V Headphone output load impedance: 32-300Ω Maximum headphone power: 160mW/32Ω Signal to noise ratio: 100dB(20HZ-20KHz) color:Black Material:metal+plastic Package Contents: 1 x Audiophile Tube Preamp 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.