Fox&';s Glidecore air spring used in the 2026 Fox 36 reduces friction while the fork is under dynamic load through its compliant design. Pair that with reduced breakaway friction compared to the previous generation air spring and you get the best 36 air spring to date. Use this air shaft assembly to change the travel of your 2026+ Fox 36 or upgrade your previous generation 2021-2025 Fox 36. Fox 36 SL uses a different Glidecore Air Shaft. Backwards compatible with the 2021-2025 Fox 36 Factory, Performance Elite, and Performance forks. Top cap is not included. You will re-use your current top cap even if you have the previous generation Fox 36.