1 Fitment: The air filter is a replacement for GPZ1100 1983-1984, for KZ1000 LTD 1977-1980, for KZ1000 POLICE 1978-1981, for Z1 900 1973-1975. 2 Protection Engine: The air filter could filter impurities entering the engine air to keep the engine clean, and increase horsepower and acceleration. 3 High Performance: Organ mesh design, double steel mesh effectively filters impurities and provides purer air, conical pattern with doublel mesh design has excellent braking power. 4 Practical: Increase in air contact area and increase inspiratory volume, long term use, easy cleaning, improve throttle response and more horsepower. 5 Compatibility: The 28-48mm universal air filter is designed and manufactured for a variety of applications, suitable for most motorcycles.