It is designed to replace broken flange(s) at the rear of the seat track. Those pieces were cast aluminum from the factory and fail under regular use. Here at VetteNuts, we had ours CNC machined out of billet aluminum so they never break! Our kit also includes the anti-rock washers that you will install while performing the flange replacement.
CS900L = Driver’s Seat - single track fix. (1 track)
CS900R = Passenger Seat - single track fix. (1 track)