Features Preamplifier: This preamplifier card can condition the incoming audio signal before sending it to the power amplifier board. Easy to use: the preamp module is compatible with 2.54mm and 5.08mm connectors, and whose output is DC12V. Good Control The preamp module adopts continuous adjustment of treble, middle, bass and volume, it is very simple. Smart Design The preamplifier module adopts two 5532 chips, which have good operating stability and high efficiency. Simple Installation This tone card comes with M3 mounting holes, which is easy to install and can be completed quickly in minutes. Specification: Item Type: NE5532 Preamplifier Chip Model: NE5532x278M12x1 Input Voltage: DC 12-25V AC 9-18V Architecture: Dual 5532 High, Medium and Low 3 Stage continuously adjustable Features: Output DC12V Input interface: approx. Interface 2.54 mm/0.10 inches, approx. Terminal 5.08 mm/0.20" Output interface: approx. Interface 2.54 mm/0.10 inches, approx. Terminal 5.08 mm/0.20" Adjustment type: treble, midrange, bass and total volume. Mounting hole: M3 (diameter: approx. 3.3 mm/0.13 inches). Material: PCB Package list: 1 x Volume Control Card 16 accessories Package List 1 x Volume Control Board 16 x Accessories