This is a pressure activated membrane switch, requiring the slightest touch (2 ounces of force), whether it comes from directly above or at a shallow angle. The rigid and durable Pal Pads are approximately one tenth inch thick. However the point at which the cable connects to the plate can often be damaged by inappropriate use. Large: 4.5" x 6" : Small 2.5" x 4" : Mini 2" x2". **$55 replacement cost.