K&N HA-1004R Race Specific Air Filter Premium Quality Upgrade Performance System. This K&N racing air filter has just two layers of cotton to provide even lower air restriction than our replacement air filter for street vehicles. Unlike K&N replacement air filters, fuel management modifications will be necessary with this racing filter. This product is for closed course competition use only. Designed to increase horsepower and acceleration. Designed for racing and track applications, not for street use. Washable and reusable air filter. Tapered Conical Air Filter. 5 in (127 mm). 0 in (0 mm). 1.3 lb (0.6 kg). 1.28 lb (0.58 kg). Air Filter Large End Diameter. 4 in (102 mm). The table below is a product-data summary and may not show every engine or trim restriction. 999 Race Specific. Reference onlyalways confirm dimensions and vehicle compatibility before ordering. BMC: FM37416RACE Honda: 17210MEL000. K&N part number: HA-1004R Category: Powersports Air Filters.