Standare U-Boat Caster:
- 4 x 1-1/4" Polyurethan on Polyolefin Annular Bearing wheel
- With Thread Guard
- Overall Load Height: 5-1/8"
- Plate Size: 3-1/8" x 4-1/8"
- Bolt Hole Spacing:  2-3/8" x 3-7/16" or 1-3/4" x 3" slotted to 2-3/8" x 3-3/8"
- Capacity up to 275 lbs. per caster.

Standare U-Boat Center Wheel:
- 8 x 2" Polyurethan on Steel or Polyurethan on Polyolefin wheel
- Roller Bearing with spanner to 1/2" bore
- Capacity up to 1000 lbs. per caster.