Round shape porthole for Boat/Yacht/RV/Industry Cars Corrosion free synthetic fittings and durable water-tight rubber seals Temper Glass for Strength, Clarity, and Chemical Resistance The two fittings can be loosened to allow you to swing open the porthole Easy to install, pre-drilled countersunk fastening holes (screws not included) Description: 4mm(0.15inch) thickness tempered glass Overall Outer Diameter: 8 inch/210mm Easy "click-in" construction Casted and polished 316 stainless steel accessories Strong ABS Molded Design, Anti-Aging, Anti-Corrosive, Ultraviolet Resistant. Diameter Opening w/ Open Window: Approx. 7 3/4inch/197mm Name: Round Portholes Size: 8 inch 21cm (21.5cm) Fit: Boat RV Colour:White Material:Stainless steel + tempered glass Package Contents: 1 x Round Portholes Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.