FB systems have distinct profile edges, similar to the Quadrat system. The FB version is distinguished by its flushed sash which visually creates a unified surface. The special shape of the aluminum sash, which shifts the window pane 5/8” further forward as in more conventional designs, allows for the use of broader glazing with a thinner wood cross-section. Quadrat FB lacks a visible slant and there is a right angle on the surface of its profiles. Much like other systems, Quadrat FB stands out with high functionality and excellent utility properties.