Relative Mesh Size
If the Mesh size type is set to Relative, Relative mesh size needs to be provided. The resulting element size is computed by multiplying the relative mesh size with the maximum edge length of the bounding box of the individual regions in a volume group.
A volume group could have multiple regions, and a mesh size is computed for each of the regions in the volume. The relative value should be greater than 0 and less than or equal to 0.125 (0 < relative size ≤ 0.125).