What material is the new air spring piston? The DebonAir+ air spring piston is made from aluminum, which can be made thinner than plastic while maintaining its structure and maximizing air volume. Related articles What has physically changed in Debonair+? Can I put DebonAir+ in my existing RockShox fork? Which parts are needed to change a MY23 RockShox fork’s travel? How does the DebonAir+ improve upon DebonAir C1? Can I retrofit the Ultimate bushing package on RockShox Select + and Select forks? Are there differences in RockShox lower legs between Ultimate and Select+?