The package contains two identical original headset bearings suitable for all Headshok and Lefty headsets. They are precisely machined to fit tightly like the original factory bearings. It is important to check the condition of the cups before replacing only the bearings, especially for Lefty and Headshok compatible frames with external cups. Frames manufactured after 2007 usually have integrated cups, and most Cannondale mountain frames now use the Si headtube. The kit only includes the two bearings and does not come with any other parts.