Our custom machined tuning indicator bolts will fit any rails with a 3/16” spacing. Ludwig makes their rails slightly smaller, and our bolts are design to fit those while in the “above pedal” orientation.
Other brands that the bolts can fit: Yamaha (tight quarters), RePercussion, American Drum Manufacturing Company/Lights. If using Lights with a 1/4” spacing, please Contact us to setup a gauge modification or to get directions for the mod.

Put the bolt into the rail, attach the nylon washer UNDER the rail, followed by spring washer and brass nut. Crimp bottom threads with pliers to prevent hardware loss.

We suggest one of two methods: crimp the last few threads with pliers, or put a dot of glue/Loctite on the end of each bolt.

If you’re missing some of these parts, please Contact us and we’ll sort it out!

For Ludwig, a typical recommendation would be:

32: D-A, plus a Dot for Bb.
29: F-C, plus a Dot for Bb, and optional D.
26: Dot (Bb), C-F. There usually isn’t enough spacing for the B to C to fit.
23: D-A, plus a Dot for Bb.
20: F-C

Set of 2: A: 1, B: 1, C, 2, D: 1, E: 1, F: 2. G: 1, Dot: 2 Fill Form

Set of 4: A: 3, B: 1, C: 2, D: 3, E: 3, F: 4, G: 3, Dot: 4 Fill Form

Set of 5: A: 4, B: 2, C: 3, D: 3, E: 3, F: 5, G: 4, Dot: 4 Fill Form