Be prepared for a difficult replacement.
This part is not a one-for-one replacement for the plastic parts.  You have to be prepared for a difficult task. You need mechanical skills, a  lot of patience, make sure you document parts placements before they are removed. Installation of this replacement part is difficult. The provided information doesn't begin to tell all the tasks that are required. The illustration is misleading and needs to be interpreted "upside down." When you finally get the part installed, be prepared to trouble shoot and adjust the items that rub and snag against each other. And, your chair will not be the same. The foot rest cannot be raised as high and moves under the weight of your legs. The back is inclined more than before.
Rating: 3 stars