The DK88 is a continental style inward opening window. Generally specified where huge openings are required or when a window is situated adjacent to a door based on this frame profile.
DK88 Window (triple glazed)
Uw = 0.74 W/m²K (1.23 x 1.48 m opening standard window)
Rw = 34 dB (-2;-5) - with standard glasses