51MM Cone Filter Rubber Top RO-5100-09. 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-5100-09
• Design: Round
• ID: 51 mm
• Length: 91 mm
• Outside Diameter Big: 80 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.  

For: 

Kawasaki
GPZ 500 84-88
GTR 1000 92-03
KZ 550 GP 82-83
GPX 750 R 87-89
GPZ 600 R Ninja 85-99
Z 550 GP 82-83
ZC 1000 Concours 86-03
ZL 600 Eliminator 86-97

Suzuki
GSX 600 F 88-89
GSX 1100 F 88-96
Katana 88-93
GSX-R 750 86-87
GSX-R 1100 86-92

Yamaha
FJ 600 84-85
FZ 600 86-88
FZR 400 88-90
FZX 700 86-87
FZR 750 R Genesis 88
XJ 900 F 83-94
XJ 600 N 84-01
Yamaha XJ 600 Diversion 92-03
XJ 650 Maxim 80-84
XJ 750 Maxim 82-83
XJ 700 Maxim 86
XJ 650 L Midnight 81
Xj 750 M Maxim Midnight 83
XJ 750 R Seca 81-83
XJ 900 R Seca 83
XJ600 S Seca 2 92-94
Xj 700 X Maxim 85-86
YX 600 Radian 88-90