The FR1TBS is a steel shim that sits between the sustain block and the base plate on a Floyd Rose 1000 Series tremolo. Its job is to correct the seating angle of the block when the geometry is slightly off — typically after a block swap, a body reroute, or when a replacement block is not sitting flush against the plate. If your bridge is level but the springs are pulling at a shallow angle, or the block face is not making full contact with the plate, a shim is what you need before you reach for a new block.

Fit is a two-part check. First, the block length plus the shim thickness has to clear your body cavity — if the combination bottoms out during a dive, the bridge cannot return to pitch. Second, the mounting screw pattern on this shim has to match the base plate it is bolting to. This part is made for the 1000 Series, so confirm that is the series you are working on. If you have swapped components across series at any point, measure your existing screw spacing and compare it before ordering.

The shim is steel. Floyd Rose used steel here to match the block material in the 1000 Series and keep the interface consistent. A softer material between block and plate introduces a compliance point that affects how the bridge responds; steel keeps the mechanical path direct.

If you are not certain this is the right shim for your setup, send us the make, model and year of your guitar and we will check it against what we have on the bench.