54MM Cone Filter Rubber Top RO-5404-100. You see this very cool big air filter mounted on big two cylinders like a CX or a BMW Boxer. (Please measure the diameter)

Specifications:

• Part Number: RO-5405-100
• Design: Round
• ID: 54 mm
• Length: 94 mm
• Outside Diameter Big: 77 mm
• Outside Diameter Small: 51 mm
• Flange: 16 mm
• Top Style: Rubber top

The filters are washable. Oil them in and you can re-use the filters again.