MIL jacks mate with MIL-type phone plugs with .25 inch (6.35mm) or .21 inch (5.34mm) diameter bushings. Numbers C11 and C12B have a non-turn locating pin which keys the jack to the mounting surface. For low contact resistance applications, jack number C12A has fine silver contacts on shunts and tip springs.
Questions? Contact Switchcraft Customer Support at 1-773-792-2700