Genuine Switchcraft premium Mil. Spec. 1/4" open frame amp input jack for vintage Fender amps. Female shorting type, two conductor with tip shunt. Looks almost identical to '50s type but offers much better contact integrity and reliability. This jack is the best you can buy for restoration and repair of vintage Fenders; it fits exactly. This jack mates with standard 1/4" phone plugs and mounts in a single 3/8" diameter hole. 3/8-32 UNEF-2A threads. I measured .370" diameter on the threads. Threaded portion of bushing measures .275" long. A complete set of mounting hardware included; nickel plated lock washer, nickel plated beauty washer and nickel plated hex nut.