The PYI PSS Dripless 0250M312 shaft seal is a dripless stuffing box and packing gland replacement for sailboat and power boat drivetrains. The PYI PSS packless dripless 0250M312 shaft seal is a mechanical seal that uses a self-aligning carbon-graphite stator to ensure a 100% watertight seal. The PYI PSS Dripless 0250M312 shaft seal will eliminate shaft wear and minimize corrosion. Save big on PYI PSS Dripless 0250M312 shaft seals for inboard shafts. The PYI PSS Dripless 0250M312 shaft seal measures Shaft Size: 50 mm, Stern Tube O.D.: 3-1/2 inches, Compressed Length: 8-1/8 inches