The US Optics FXD Bubble Level Rail Mount is a fixed-position leveling device designed to mount directly to Picatinny or Weaver-style rails.
- Type: Fixed bubble level, rail-mounted
- Mounting: Picatinny/Weaver rail (MIL-STD-1913)
- Material: Aluminum
- Finish: Matte black
- Use: Precision shooting, hunting, competition










