These 1/8" thick clear Poly-carbonate windows with NACA ducts are direct replacements and designed to fit in the original frame of the 911 through 993 (Not "pop-outs" on early 911's). The NACA ducts fit a 3" hose. Weight is 2 lbs per pair. Quarter windows sold and priced in pairs. If you are looking for a flush frame with the quarter window and NACA duct, please see GT Racing part #63CN
