The sustain block is the brass slug that hangs below the base plate and anchors the three springs. When the original block cracks, strips its saddle-screw threads, or corrodes through years of heavy use, this is the part you replace it with. This is a Floyd Rose Original series block in nickel-plated brass, 35mm, part number FROTB35P, made in Germany.

Fit is decided by two things. First, block length has to match your body cavity — 35mm has to clear the route cleanly at full dive without bottoming out, and has to leave the springs sitting at the correct angle at rest. Measure your existing block before ordering; do not guess. Second, the mounting screw pattern has to match your Original series base plate. This block is cut for the Floyd Rose Original — if your base plate is from a different series, the holes will not line up.

Brass shifts attack character relative to steel or zinc — slightly warmer, with a rounder initial transient. That is a tonal consideration, not a fit one. The nickel plating keeps the contact surfaces clean and resists the string-lubricant buildup that works into the saddle seats over time.

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