The E series utility plugs are straight-sided, thin-walled closures designed to protect threaded connectors. The flanged end makes for easy removal in hard-to-reach areas. The versatile design of these plugs make them ideal for use in a variety of threaded and non-threaded applications. : : A: 1.977, B: 1.917, C:.63, D: 2.09, TOFITTHRSZ: 2.