Feature:1. Pre Wired Circuit: P1 is connected to the positive pole of the neck pickup, P2 is connected to the positive pole of the bass bridge pickup, and GND is connected to the negative pole of the 2 pickups.2. Improve Sound Quality: This bass subwoofer boosts the sound of your electric bass and makes your music more penetrating.3. Fine Workmanship: The workmanship of the amplification circuit is exquisite, and the terminals are sensitive and resistant to plugging and unplugging.4. Plastic Housing: The plastic shell of this bass woofer amplifier line is molded in one piece, durable and wear resistant.5. Good Choice: This bass bass amplifier circuit is the perfect choice for luthiers or musicians who love to DIY, and it is also a product for you.Specification:Item Type: Electric Bass Preamp CircuitMaterial: Plastic and metalBass: 14dB 80Hz B100KMidrange: 8dB 900Hz B100KTreble: 23dB 3-7KHz B100K.Package List:1 x Electric Bass Preamp CircuitNote:If you do not know how to install the circuit, please consult a local luthier Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.