Offered is an Antique / Vintage ~ Large Signal Green Convex Nautical Lantern Lens.  It is glass and maker unknown.  It stands 5-3/8" tall overall X about 5" wide and weighs 1.165 lbs.  It has 4 outer ridges and 3 outer ridges either side of the middle area.  It has a two edge flakes, and one sharp fresnel outer ridge flake missing ( 2nd to last photo shows that one best).  The edge flaws may not be seen when installed?  If you have a busted out lens, this is better than nothing.  Ask any questions, I don't know what it goes to?  Perkins Marine Lantern?  Ships packed well, 2 lbs, USPS priority mail and cost depends on your location.  Thanks for looking!