If you&';re looking to increase or decrease the travel of your 2021 or newer Fox Float 36 fork, simply snag one of these air shafts in the travel which you&';d like to set your fork to, and swap it into your fork! The new 2021+ Air Shaft boasts a larger negative air volume chamber compared to the previous generation. Fits all 2021+ Fox 36 Factory Series, Performance Series Elite, and Performance Series forks. Does NOT fit the Fox 36 Rhythm. Includes brand new seals pre-installed, plus a new foot nut and crush washer. NOT BACKWARDS COMPATIBLE with older Fox 36 forks. *NOT backwards compatible with older model years.