In the first phase, the sound of the engine on the ZZR 1200 completely changed. It became sweeter, quieter, and works smoother and more smoothly. I will come back when I have more kilometers and when I change the mufflers. After the first kilometers and with the closed (muffler) exhausts, the filter impresses at medium and high speeds where it provides exactly the air it should and the engine accelerates and revs up quickly and effortlessly, giving the impression that you have a more powerful motor. I believe that just the combination of the filter with an open exhaust will give impressive results at medium to high speeds without changing anything else on the engine!