Adapts any non-Boost SPIKE or OOZY front hub (15x100, 20x110), to fit with Boost (15x110) forks. Left and right hub adapter caps, 5mm brake rotor spacer, and 6 extra-long brake rotor bolts included. Compatible with all OOZY front wheels. Compatible only with SPIKE and SPOON front wheels produced in 2016 or later (with Spike Hubs).