Coaxial connector system with adaptor

A connector system includes an adapter with a first mating portion, a second mating portion and a transition portion. A continuous outer wall extends across the first mating portion, the transition portion and the second mating potion. A first terminal positioned in the adapter. At least one receptacle has a receptacle mating section and a receptacle transition section. A continuous receptacle outer conductive wall extends across the receptacle mating section and the receptacle transition section. A receptacle inner wall extends perpendicular to the receptacle outer wall. A second terminal is positioned in the at least one receptacle. A retention member is provided in the receptacle mating section. The continuous outer wall and the continuous receptacle outer wall form a grounding shield minimizing signal leakage from the first terminal and the second terminal.