GR400 mesh has a raised surface finish. GR400 is a more open grade of our heavier exanded meshes but with a heavy strand, making it slightly higher loading than GR300.
The LWM (Long way mesh) is across the sheet while the SWL (Short way length) is along the length of the sheet. Thickness is the thickness of the sheet being used to cut the mesh from. The strand is the width of each slice.
For more specific detail about Gridmesh including loading specifications please follow this link to Gridmesh Technical.