The Pore Fluid (ID 00) allows to change the fluid type. The Voxel Length is the size of the voxels in the chosen units. When entering a Voxel Length, the number of voxels corresponding to the pleat size in the three spatial dimensions (NX, NY and NZ) is calculated automatically according to the pleat shape specifications. That is the reason that NX, NY, and NZ cannot be modified. As a guideline, the smallest media thickness should be resolved by at least 5 voxels.