It is a Hinged hidden sash window system with frame depth of 70 mm . Seen surface of only 70 mm from the outside . Extraordinary increase in luminosity . Possibility of incorporating hardware with concealed hinges . Max glazing thickness 35mm and weight 150kg . opening posiibilities of Side hung, turn & tilt of 1 or 2 sashes, tilt & parallel, bottom hung . Possibility of bicolor systems , Color powder coating (RAL, mottled and rough) Wood effect powder coating , Anti-bacterial powder coating ,Anodized.American Oak, Sapelly, Mellis Pine and other timber options available on request.