"Feature: 1. The sound is very powerful, and the treble and bass controls provide rich tone changes. Provide better performance for the use of your musical instrument. 2. The installation is convenient and quick, and it can be completed in a few minutes. The use effect is good, and it is suitable for two-section bass amplifier lines. 3. The product has pre-wiring, so there is no need for additional complicated installation steps, and it can be used by installing relevant wiring according to its own needs. 4. It can restore the use effect of your product more quickly without affecting the original use effect, and it is a good substitute. 5. Before welding, you can test the wires of the product and your original musical instrument to see if everything is normal. Note:The wiring diagram is not included,many customers have difficluty in installing the Circuit,please double check if you could install it before you buy. Specification: Material: Metal Color: Multicolor Weight:92g Package Includes: 1 x Bass Pickup Preamp Circuit 2 x Gasket 2 x Spacer 1 x Screw"