A wafer edge-defect detection system with a probe assembly having one or more capacitive plates conforming in edge shape to an edge shape of a wafer; and processing electronics for electronically driving the one or more capacitive plates and for sensing an electrical signal representing capacitance between each one or more plates and the wafer. At least one of intervals between effective vibration regions of adjacent speaker units is set to a predetermined length. The peer attachment points are respective endpoints of a set of one or more LAN segments defined within the Ethernet Bridging domain. The detection unit verifies data to be displayed in a driver circuit, or detects a current value in the circuit. A retractable air supported hypalon cover protects the large primary mirror structure.