Have you lost a seat overboard or do you have a problem with seat comfort? The Dreher Carbon seats have the same comfortable seat top, but an increased strength to weight ratio. As a result the seats weigh less and therefore have improved durability. The new medium seat top design can accommodate a track width of 16.5-23 cm. The old medium seat design can accommodate a track width of 23-28 cm. The large seat top design can take a track width of 23-30 cm. The seats are made with three size of aluminum seat seat supports (1.75 cm, 2.25 cm or 3.25 cm). The nylon seat support comes only in low height (1.75 cm).