An apparatus for use by individual to repair and replace tread on the bottom of a pair of shoes is disclosed. The shield further includes a second member having substantially planar front and rear surfaces and an edge portion engageable with the edge portion of the first member. The amplifier stages have a mutually different delay and the primary and the secondary am amplifier stage are each coupled to an input of the module. The first region scaled-down line width and the second region original line width are substantially different from each other.