["Features:\nDual channel input, subwoofer output, then the output amplifier,can not directly connected to the speaker\nThe multi-stage filter, better effect \n\nSpecifications:\nPhase Adjustment: 0; 180\nPower supply voltage: for DC 9V-32V for DC single power supply\nThe phase adjustable\nPotentiometer from left to right: frequency adjustment, volume control\nThe cut-off frequency: 22HZ-240HZ\nPotentiometer shaft center to center spacing: 3cm\nSpecial note:\nThis board is a preamp board, and is not designed to be directly connected to the speaker. It must be connected to the subsequent stage of an amplifier board for this pre-amp to work.\nThe so-called low-pass filter to filter out the human voice board is more than treble part, retain the low frequency part is amplified to improve the reproduction efforts, people will not hear the sound of musical instruments and high-frequency sound during playback. The buyer must understand knowledge of this area.\nPCB size: 6.1*2.6cm/2.40*1.02inch\nNo Retail Packages\nQuantity: 1Set\nNote: Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!\n\nPackage include:\n1 * Module\n1 * Cable"]