A rubber ring for a gasket has a first bulging portion composing a seal portion; a second bulging portion composing an attachment portion; and a depressed portion between the first bulging portion and the second bulging portion. The low spatial frequency is used to establish the rigid body motions to be applied to the individual sub-apertures of interferometric data in stitching them together to give a full map at high resolution of the whole part. The transflective film is positioned between the light guide panel and the fixing face for reflecting a part of light from the light guide sheet so that the part of light passes back into the light guide panel. A datapath is provided which, in addition to the foregoing, includes array IO blocks, responsive to the datalines from each quadrant to output data to a data read mux, data buffers, and data driver pads. A method for treating snow moulds comprises applying the mixture before the onset of continuous snow cover, in at least one application.