The XRD installation base is designed for the type F flat roof window – it allows to raise the window above the roof by 5.9" (15cm). It reduces to a minimum time required to install the window in roofs where it is necessary to raise the window (e.g. green or gravel roofs).
Lengthened frame element, the so-called fin allows connection of the base with water insulation of the roof
In case of the construction of a higher base it is necessary to cut protruding part of the fin around perimeter and overlap bases one on top of the other.