A grout float, including a blade and a pair of core sections defining a handle. The body of the piston of the present invention is contoured in manner to reduce the undesirable build-up of oil pressure that frequently occurs at the oil control ring or rings when the piston is in operation. When light passes through the photomask, the arrangement of the transparent, semiopaque, and opaque optical controlled elements forms the shading patterns, and these are exposure patterns in the exposure process. The controller is responsive to a request received from one of the plurality of networks through the transceiver for accessing the module to retrieve the stored information and for transmitting the retrieved information to the requesting one of the networks through the transceiver. An end of seasoning is determined when a parameter including an internal pressure of the processing chamber has become stable to a steady value with plasma processing time.