The PYI PSS Packless 02312412 shaft seal is a dripless stuffing box and packing gland replacement for sailboat and power boat drivetrains. The PYI PSS packless dripless 02312412 shaft seal is a mechanical seal that uses a self-aligning carbon-graphite stator to ensure a 100% watertight seal. The PYI PSS Packless 02312412 shaft seal will eliminate shaft wear and minimize corrosion. Save big on PYI PSS Packless 02312412 shaft seals for inboard shafts. The PYI PSS Packless 02312412 shaft seal measures Shaft Size: 3-1/2 inches, Stern Tube O.D.: 4-1/2 inches thru 4-5/8 inches, Compressed Length: 9-3/4 inches