An adaptor box for mounting a fixture to a low voltage track having a housing containing contacts with one of their ends formed with female contact portions which are arranged on above the other in the housing to provide a common mating axis in the housing connection to a male coax connector of the fixture and other ends forming feet protruding from a mounting head of the housing for connection to respective busses of the low voltage track. Contact separating and locating protuberances are molded on the interior of the housing and an insert molded with additional contact locating and separating protuberances is assembled through a front opening in the housing.