Features: brand new and high quality Volume B50K; Pickup MN250K. Bass: +/- 14dB 80Hz B100K; Middle: +/- 8dB 900Hz B100K; Treble: +/- 23dB 3-7KHz B100K. P1 should be wired with neck pickup positive; P2 should be wired with bridge pickup positive; GND should be wired with two pickups negative. High quality preamp, not inferior Circuit made in cheap factories. Please consult your local luthiers if you don'for t know how to install the circuit. Specifications: Material: Metal、Plastic Color: As The Picture Shows Package Weight: approx.90g Size: approx.4.0x3.1x1.1cm/1.57x0.43in (More Size Details, Please See Photo.) Note: Please allow 1-2cm 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: 1Pc x Bass Preamp Circuit Volume B50K; Pickup MN250K. Bass: +/- 14dB 80Hz B100K; Middle: +/- 8dB 900Hz B100K; Treble: +/- 23dB 3-7KHz B100K. P1 should be wired with neck pickup positive; P2 should be wired with bridge pickup positive; GND should be wired with two pickups negative. High quality preamp, not inferior Circuit made in cheap factories. Please consult your local luthiers if you don'for t know how to install the circuit.