When Feedback Sports acquired the line of bicycle wash and work stands in the early 2000’s, only a limited number of the Ultimate collars and fittings remained available. Once we ran out of these parts, we were no longer able to produce the replacement collars and fittings for certain Ultimate products. Since these parts have been redesigned to different standards, unfortunately the current collars and fittings are not compatible with certain Ultimate generation repair stands. If you have a discontinued fitting (listed in our replacement parts), please feel free to contact tech@feedbacksports.com for alternative options on what you can do.