Six bridge saddles are held against this plate by string tension, individually adjustable both for height and intonation. Another of the components which make up the tailpiece consists of a solid block of metal, commonly made of zinc, but aftermarket products can be made out of materials such as titanium or brass (often like the saddles). The different compositions, as well as its mass, helps to determine the quality of the sound of the guitar. The block is secured to the base plate by three machine screws and resides in a cavity routed all the way through the guitar's body. In this cavity, up to five coil springs tether the end of the bridge block to the body, counteracting the pull of the strings, should this be the setup choice for the guitarist. There can even be differing sizes of tremolo arms in thickness depending on the date and country of manufacture.