alpha Racing's Airbox Funnel Kit (Short), fits OEM air box for BMW S1000RR and HP4. This will require engine tuning via alphaRACE Flash Tuning Device, ECU Flash, HP Parts Race ECU or other tuning method offered by us or your local professional tuner with a dynometer. Only for use in addition to other engine modifications like camshafts, high compression pistons, increased displacement "stroker" engines, etc. Engineered for more horsepower, increased power in high rev range, no loss of power in bottom and mid range power-band. 4 airbox funnels short, and retainer clips included. Weight: 0.075 kg.