sino-grating
https://www.sino-grating.com/products/perforated-o-grip-plank-grating/
The special surface of the O-Grip anti-skid plank is composed of larger concave holes and raised punched holes. The raised punched holes can provide greater anti-skid protection and anti-skid performance. The larger concave holes can leak liquids, mud, gravel and other debris. The metal plate surface of the O-Grip anti-skid plank provides slightly less support than ordinary anti-skid plates, and the weight is lighter than ordinary anti-skid plates, which is easier to install.