This open-frame phone jack is constructed with leaf spring contacts, phenolic wafer insulation stacks, and a nickel-plated steel mounting frame. Designed to accept standard 1/4-inch (6.35mm) mono jack plugs, it provides mechanical switching and signal termination for vintage radio chassis, audio patch bays, and industrial equipment.

The open frame layout allows clear visibility of contact engagement and straightforward access for cleaning, adjusting spring tension, or soldering leads to the integrated solder lugs. The threaded front bushing includes mounting hardware for panel installation.