A method for etching features in a silicon oxide based dielectric layer over a substrate, comprising performing an etch cycle. The light guide for endoscopes is constituted by a plurality of bundled optical fibers, for propagating an illuminating light beam, which is focused and caused to enter a light input end facet thereof, to a light output end facet thereof, to emit the illuminating light beam onto a portion to be observed. A pair of shallow generally rectangular recessed pockets on each of the elongate lateral sides of the pad receive the fingertips of the offensive lineman and approximate the proper hand placement for an offensive lineman to engage a defensive lineman.