Genuine Keihin N424-330 (Series 3F) short slow jet. The primary OEM slow jet for Keihin FCR-MX carburetors on modern 4-stroke motocross/enduro bikes. Distinct from aftermarket FCR pilot jets (which are much longer at 28mm). This 13mm length version is used in factory-installed OEM applications on Honda CRF, Yamaha YZ-F, KTM SX-F, Kawasaki KX-F, and Suzuki RM-Z models.