The stop cock is a valve that can be turned to shut off or allow the flow of water through a pipe. It typically has a lever or knob that can be rotated to open or close the valve. The stop cock is designed to be hidden behind a wall, usually within a valve box or plumbing access panel. This concealed design helps maintain a neat and streamlined appearance in the living space. The wall flange is a decorative and functional component that covers the hole in the wall through which the stop cock is installed. It provides a finished look and helps to protect the surrounding wall from water damage.