Features: Brand new and high quality Passive Preamplifier Active Speaker Volumes Controller: precise Volumes adjustment, no loss, suitable for all types of devices and external active Speaker. Professional 128mm Fader Switches for Volumes Adjustment: the accuracy error of fader switches is small, the left and right channel is better, and there is no loss of sound details. Size: the Volumes adjuster with intuitives scale makes the desktop Volumes adjustment more convenient and precise. Simple Installation: Be used once inserted, convenient to install, signal source adjustment, no loss of input and output, perfect for enjoy different hearing experience. Suitable for Equipment with Excessive Sound Gain: such as computer sound card, digital player, active speaker, rear power amplifiers and other equipment. Specifications: Input and Output Impedance: 10-50KΩ Frequency Responding: 20-20kHz Distortion: <0.002% Signal Gain: 0dB Volumes Control: Adopt professional 128mm fader Volumes Size:Approx.170x69x50mm/6.69x2.71x1.96inch Package Includes: 1Pc Volumes Controller note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual of the item.