Jacks are standard 2- and 3-conductor phone jacks with extra long threaded bushing for mounting in panels/chassis up to 1.25 inches thick. Metal bushing virtually eliminates hum pick-up, and is ideal for electric guitar and speaker connections. Jacks mate with standard commercial phone plugs. See plug section for mating plugs. Jacks mount in a single .469 inch diameter hole. Rugged cable clamp protects connections from twisting and pulling stresses.