MirageDrive Glide Tech Sprockets are compatible with V2 and original GT MirageDrives. They can also be used on v1 MirageDrives, but only with V2 fin masts (v1 sprockets are no longer available).
These GT sprockets are not compatible with the newer GT KU MirageDrives. See GT KU Sprocket
Hobie MirageDrive Glide Tech Sprocket