Curb boxes and accessories are underground devices that protect valves within water, wastewater and gas utility lines. They also permit access for valve operation. Curb boxes and accessories telescope outwards and consist of upper and lower sections. The upper sections are made of steel pipe and are designed to telescope up or down within a base casting that is often made of iron. The upper sections are held in place by a clip ring at the top of the base, and differ in terms of maximum extension. Swaged lugs at the bottom of the upper section are designed to fit into a cast slot in the base, preventing the upper section from turning during the removal of the lid or pentagon plug. Typically, the pentagon plugs for curb boxes and accessories are made of cast brass.