ORIGINAL Vintage Bronze Round Porthole Glass --15.5 POUNDS - 12 3/4 INCH- OVERALL DIAMETER. THE MIRROR WAS PUT ON WITH CAULKING MATERIAL OVER THE ORIGINAL GLASS. THE ORIGINAL RUBBER GASKET IS SOFT AND TORE SOME WHEN I OPENED IT UP TO PHOTOGRAPH. THIS IS THE REAL DEAL. ONLY MARK IS 36 ON THE HINGE AREA. THE SIZES ARE 12 3/4 INCH OVERALL DIAMETER. FRONT WITH GLASS IS 10 INCH THE GLASS ITSELF IS 7 3/4 INCH. THE BACK OF THE HATCH IS THE RIM TO FIT INTO A HOLE IS 9 1/2 INCH.  THE REAL DEAL ORIGINAL. THE GASKET EITHER NEEDS REPLACING OR IF YOUR NOT GOING TO USE IT ON A BOAT JUST CLOSE THE HATCH AND TOGGLE DOWN THE BOLTS AND LEAVE IT AS IT IS. IT TAKES A BOX TO SHIP THIS.