Important - Check the measurements of this before buying..

Also available is this: Kawasaki ZRX-1100, ZRX1200 97/09 (KA-1199)

Specifications
Filter Material    Cotton Gauze
Height    4.375 in (111 mm)
Inner Wire    No
Inside Diameter    3 in (76 mm)
Outside Diameter    4.25 in (108 mm)
Top Style    Open
Top Material    None
Air Filter Shape    Round
Flanges    None
Package Contents    1 Air Filter
Washable    Yes
Weight    0.7 lb (0.3 kg)

Product Box Height    7.25 in (184 mm)
Product Box Length    4.63 in (117 mm)
Product Box Width    4.63 in (117 mm)

Vehicle Applications
1990 Kawasaki ZXR400 400

Possibly also fits the below (Check measurements)
KAWASAKI  ZRX1100
KAWASAKI  ZRX1100 II
KAWASAKI  ZRX1200 DAEG  09-14
KAWASAKI  ZRX1200R  01-08
KAWASAKI  ZRX1200S  01-08
KAWASAKI  ZRX400  94-00
KAWASAKI  ZRX400 II  94-00