From the Manufacturer

Keep the mud off your fork and out of your eyes with the official FOX Mud Guard designed specifically for FOX 36, 38, 40 and Podium models. This direct-mount fender uses a proprietary and sturdy 4-point attachment to secure to the fork and comes in two lengths for tailored protection. 

NOTE: The model year of your fork determines which Mud Guard will fit - please check using your Fork serial number before purchasing. This product does not fit Rhythm Series forks, or any fork before model year 2021.