A connector is disclosed. The connector includes a conductive housing. The conductive housing includes a wall region enclosing a space for receiving an adapter. The conductive housing also includes an annular end piece extending radially inward from a first end of the wall region and terminating the space. The annular end piece includes a flat annular surface, and a raised deformable annulus mounted on the flat annular surface. The raised deformable annulus is of a height such that an insertion of the adapter into the space deforms the raised deformable annulus to generate a physical contact connection between the flat annular surface and the adapter.