Machined 4 string bass bridge is computer designed and made out of heavy gauge brass (not that cheap flimsy stuff). The back block covers those ugly string balls, giving your bass guitar that clean look. Comes with Allen wrench's for height adjustment and intonation as well as mounting screws. This is a professional quality, plated Brass, direct replacement for a traditional 5 hole, 4 string Fender bass bridges. It will mount without any modification to the bass. Oversized Nickel Plated Brass Saddles for Outstanding Sustain!