Description: Adopts NE5532 front chip for for better performance. High quality potentiometer contacts well, stable for audio output. PCB with 1.6mm thick double-sided sheet thickness of 2.0 oz copper spray tin process, to ensure the size of the current good performance, excellent quality of the PCB. The fully enclosed dust potentiometer, performance is more stable, more durable than the ordinary potentiometer. Alignment of the entire circuit board layout is very strict and reasonable, the overall PCB traces with little grounding method. Stable and reliable, steady and low-frequency strong signal to noise ratio is very good, wide dynamic range; clear details, excellent transient response and play a variety of music rise to the occasion, a very good performance in the playback environment of the family. Specification: Material: ABS + Metal Panel size: Approx 90mm*23mm Center hole distance: 35MM Operating voltage: DC/AC 9V-30V Number of Channel: Dual-channel Audio Package Includes: 1 Piece NE5532 Preamplifier Board 2 Pieces Lines(8 Pack) Note: Please allow 0.5-1 inch difference due to manual measurement.(1 inch=2.54cm) Please check the size measurement and the picture carefully before making payment. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Please understand,Thank you.