The air inhaled at full throttle opening is huge and super fast. On the other hand, when the throttle is OFF, inertia works, and the intake air is compressed in front of the closed throttle. The next time you open the accelerator, the negative pressure becomes larger than the sealed cleaner box with the compressed recoil, resulting in higher filling efficiency. Thus Honda NA's inspiration system is very clever and important. While reducing the resistance of the intake air, on the one hand it is also the best air cleaner that is effective even for rainy dust with high dustproof effect.