The Schüco Façade FWS 60 CV (Concealed Vent) system harmoniously combines slimline face widths with a high degree of functionality and optimum thermal insulation With a face widths of just 2-3/8” (60 mm), opening units and fixed lights are indistinguishable from the outside. On the flush, closed inside, only a slender shadow gap and the window handle betray the presence of the window sashes.