For use with Model C, D, E and Dynamic Indoor Rowers. One of the 3-1/4 inch wide top seat rollers (two per machine; sold individually) that runs on the stainless steel track on the monorail. Includes mounting hardware (nut, bolt, and spacers) that hold the roller on the seat frame.

Concept2 Tip: 

If your seat does not run smoothly back and forth on top of the rail as you are rowing, make sure the stainless steel track and roller surface are clean. (Use glass or surface cleaner like Windex.) If the rollers and the rail are clean and the ride is still rough, new seat rollers may correct the problem.