Original Cane Creek adapter crown race for using a 1 1/8" steer tube (30mm crown race seat) with a 1.5" or 52mm lower bearing. If you have a tapered frame using a 52mm bearing and want to use a 1 1/8" straight steer tube, this is the easiest conversion. Integrated seal helps keep your bearing clean so it lasts longer and stays quieter. This crown race is a lighter weight alloy (14 grams) than the other steel option available (39 grams).
In the case of Cannondale Si headtubes, you can use this crown race in conjunction with KP205 and replicate the fit of KP058.
WH726 bearing pictured is not included in the kit.