Features: No power supply designs, can be directly inserted and used, no input and output signals loss, switches transmission. Two adjustment methods: 1. by gains adjustment, 2. by frequency adjustment. Usage: mainly used to selects common output devices and switches various stereo signals inputs. If there are two stereo signals sources (such as MP3 player, video game, mobile phones, tablet, computer, recorder), the device needs to output to the power amplifier or active speakers. Two sets of stereo source switchers solve the complicated line blocking operating. As long as the required input device signals source is uniformly connecting to the switches, it can be easily selected. The input and output standard adopts interfaces designs, and the switches adopts accurate 2-position manual button switches. Specifications: Component:ABS Voltages: 12V Frequency: 150Hz-40Hz. Gains: 0db to -12db Package Includes: 1Piece Bass Control Knob note: Please allow 1mm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color of the item. No power supply designs, can be directly inserted and used, no input and output signals loss, switches transmission. Two adjustment methods: 1. by gains adjustment, 2. by frequency adjustment. Usage: mainly used to selects common output devices and switches various stereo signals inputs. If there are two stereo signals sources (such as MP3 player, video game, mobile phones, tablet, computer, recorder), the device needs to output to the power amplifier or active speakers. Two sets of stereo source switchers solve the complicated line blocking operating. As long as the required input device signals source is uniformly connecting to the switches, it can be easily selected. The input and output standard adopts interfaces designs, and the switches adopts accurate 2-position manual button switches.