A wastewater treatment system having a first solid-liquid separation unit, a membrane aerated biofilm reactor, a second solid-liquid separation unit and an anaerobic digester. The mechanism comprises a housing that supports two hinge plates for pivoting motion that brings the ring members to either an open position or the closed position. An example multiplexer may include a single piece power monitor assembly that includes a collimator lens array, a focusing lens array, and a slot integrally formed therein. The client is allowed to use the content under the conditions defined in the previous license information and the conditions defined in the updating license information without obtaining new rights information for the updated client module.