The Transitional Flow Interface can be thought of as having a mesh in physical space (represented by the mesh generated by COMSOL Multiphysics) and a mesh in velocity space (represented by the quadrature). Accurate solutions should not vary greatly with the physical mesh or with the quadrature. Close to the slip-flow regime, smaller quadratures provide a good degree of accuracy, but a finer mesh in physical space is required. As the flow becomes progressively more rarefied, more degrees of freedom are required to capture the behavior in velocity space more accurately, and consequently a larger quadrature is required. A coarser spatial mesh can, however, be employed.