4 mm scale sash window with a two pane over two pane arrangement.  Precision laser cut from 0.6 mm laser board, a complete window frame is constructed of two layers forming the complete frame.  Pre-cut glazing is also provided in order to complete each window frame.  Frames are designed to be fitted by passing them through the rear of the building wall.  
 
Instructions detailing how the window frames  are assembled are available to download.