The drip free self aligning Tides Marine SureSeal FSK-2500-3500-0 inboard propeller shaft seal is made from fiber-reinforced composite material, and is unaffected by temperature and will not absorb water. Order your Tides Marine SureSeal FSK-2500-3500-0 prop shaft seals today from Deep Blue Yacht Supply and save. The Tides Marine SureSeal FSK-2500-3500-0 measures Shaft Size: 2-1/2 inches, Stern Tube O.D.: 3-1/2 inches, Compressed Length: 7-1/2 inches