The drip free self aligning Tides Marine SureSeal FSK-1000-2500-1 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-1000-2500-1 prop shaft seals today from Deep Blue Yacht Supply and save. The Tides Marine SureSeal FSK-1000-2500-1 measures Shaft Size: 1 inch, Stern Tube O.D.: 2-1/2 inches, Compressed Length: 7-1/4 inches