Trombone rotor stop arm retaining screw.
Fits models:
- 536L / new model number JTB1100F
- 536RL / new model number JTB1100FR
- 536S / new model number JTB1100FS
- 636L / new model number JTB1150F
- 636RL / new model number JTB1150FR
- 636S / new model number JTB1150FS
- 538L / new model number JTB710F
- 538RL / new model number JTB710FR