brand new and high quality Features: Made of high quality material, solid, durable, good performance and long service life. The board features a very high signal-to-noise ratio and strong anti-interference ability. When there is no signal input, no noise is heard near the speaker. The adjustment potentiometer is fully sealed. The input and output terminals are made of pure copper terminals, and the wiring is very convenient. The op amp adopts Texas NE5532, and the IC for seat can be soldered at any for time to change the op amp, and the effect brought by different op amps can be improved. It is designed with LED indicators to monitor the power status in real for time. Filter Board only, other accessories demo in the picture is not included! Specification: Material: PCB Board, Electronic Components Power supply voltage: DC10-24V, single power supply Frequency range: 22Hz-300Hz Audio input: Mono or Two-channel Audio output: Mono Size: app.7.8 x 3.2 x 0.16cm/3.07 x 1.26 x 0.06in Fixed Hole Center Distance: app.7 x 2.4cm/2.76 x 0.94; Hole Dia.: 0.32cm/0.13in Potentiometer Center Distance: app.3.25cm/1.28in Color: Light Green Quantity: 1 Pc Note: No retail package. Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1 x Filter Board