Exterior Porthole. This item is made of solid brass. Wt approx. 16 lb. Glass viewing area 10.25″D. Inner flange (spigot) depth 1.75″. Flange outside diameter 12″ flange 1/8″ thick. Porthole is perfect for use in interior and exterior doors, the 2.0″ Deep flange will easily adapt to all flat surfaced doors and adjust to all doors up to 2.5″ thick.