Midwest Optical Bi1300-40.5

Midwest Optical SU27-40.5, Step-Up Ring, from M27 x 0.5 To M40.5 x 0.5, 42 mm Outer Diameter, 24.5 mm Clear Aperture

Midwest Optical SD46-40.5, Step-Down Ring, from M46 x 0.75 To M40.5 x 0.5, 49.8 mm Outer Diameter, 39.7 mm Clear Aperture

Midwest Optical SD48-40.5, Step-Down Ring, from M48 x 0.75 To M40.5 x 0.5, 49.8 mm Outer Diameter, 40 mm Clear Aperture