The Model C is a manual wall- or ceiling-mounted screen for larger rooms with permanently lubricated steel ball bearings combined with nylon bushings and heavy-duty spring assembly for smooth operation. The Model C does not feature the Controlled Screen Return for quiet and smooth return to the case. See Model C with CSR for this feature.The Model C is a manual wall- or ceiling-mounted screen for larger rooms with permanently lubricated steel ball bearings combined with nylon bushings and heavy-duty spring assembly for smooth operation. The Model C does not feature the Controlled Screen Return for quiet and smooth return to the case. See Model C with CSR for this feature.