The surface has embossed (d = 4 mm) and debossed (d = 18 mm) holes that are arranged in staggered rows. The open area for standard grating widths is approximately 21 %. Graepel-Special 4-18 has high anti-skid values as well as a large displacement space and a good drainage effect. The maximum embossed field is 460 mm.
This special perforation is suitable for very different purposes, e.g. for indoor walking surfaces in industrial plants. As facade cladding, it provides light transmission and good ventilation while protecting against excessive sunlight.