This is a model of the 3rd generation tremolo (vibrato) system as found on PRS guitars. This is a fully featured model, including threaded screws, correctly adjusted saddles, saddle springs, tremolo arm grub screw, tremolo springs, and pivot screws. The pivot screws are cut off at the level they would be mounted on the body, to provide an easy mating surface. Modelled in SolidWorks and rendered using KeyShot.

From the PRS website:

Back in 1984, Paul Reed Smith was granted a patent on his tremolo system. The design elements are simple and resemble the traditional fulcrum tremolo but with some important differences.

In the front of a PRS bridge, the six mounting screw holes are counter-sunk from underneath, providing six brass knife-edge fulcrums. These rest against the six notched brass body mounting screws. This knife-edge set-up ensures that the bridge will return to pitch after use.

The pocket in the tremolo bridge keeps the six individually adjustable saddles from moving sideways, thereby eliminating another traditional cause of tuning instability.

The tremolo block is drilled out so the ball ends rest right up under the bridge base plate. This leaves less string behind the bridge saddle so there is less chance of detuning.

There are no rough edges.

The bridge is made of brass, a metal that rings beautifully. The block, intonation screws, height-adjustment screws, and the string slots on the saddles are all left un-plated for increased sustain and fidelity of tone.

The unthreaded tremolo arm fits into a hard plastic sleeve staying where you put it, via a small set screw on the side of the bridge that faces the tail end of the guitar (where the intonation adjustment screws are located) therefore it will not wobble or break off in the block.