A connector for connecting to a co-axial cable having an inner conductor and a braided outer conductor layer, the connector comprising: a body portion comprising a front end and a rear end, the body portion defining a bore; a contact member comprising a circumferential portion and at least one protruding member, wherein: the contact member is electrically conductive; an outer surface of the circumferential portion is at least partially disposed within the bore; and the at least one protruding member protrudes from the circumferential portion within the bore; an inner sleeve at least partially disposed within the circumferential portion of the contact member; a rotatable coupling nut rotatably coupled to the inner sleeve; and a conductor retaining member (900,1260,1280,1550) centrally disposed within the inner sleeve, the conductor retaining member configured to receive the inner conductor of the co-axial cable such that the inner conductor is free to pass through the conductor retaining member (900,1260,1280,1550) in a first direction toward the front end of the body portion, and is restricted from passing through the conductor retaining member in a second direction away from the rotatable coupling nut; characterised in that: the rotatable coupling nut is electrically conductive and is electrically coupled to the contact member; an outer surface of the circumferential portion of the contact member is at least partially disposed within the bore at the front end of the body portion; the at least one protruding member protrudes from the circumferential portion within the bore towards the rear end of the body portion; and contact between the contact member, inner sleeve and rotatable coupling nut is arranged to provide a ground path between the braided outer conductor layer and the rotatable coupling nut. a body portion comprising a front end and a rear end, the body portion defining a bore; a contact member comprising a circumferential portion and at least one protruding member, wherein: the contact member is electrically conductive; an outer surface of the circumferential portion is at least partially disposed within the bore; and the at least one protruding member protrudes from the circumferential portion within the bore; the contact member is electrically conductive; an outer surface of the circumferential portion is at least partially disposed within the bore; and the at least one protruding member protrudes from the circumferential portion within the bore; an inner sleeve at least partially disposed within the circumferential portion of the contact member; a rotatable coupling nut rotatably coupled to the inner sleeve; and a conductor retaining member (900,1260,1280,1550) centrally disposed within the inner sleeve, the conductor retaining member configured to receive the inner conductor of the co-axial cable such that the inner conductor is free to pass through the conductor retaining member (900,1260,1280,1550) in a first direction toward the front end of the body portion, and is restricted from passing through the conductor retaining member in a second direction away from the rotatable coupling nut; characterised in that: the rotatable coupling nut is electrically conductive and is electrically coupled to the contact member; an outer surface of the circumferential portion of the contact member is at least partially disposed within the bore at the front end of the body portion; the at least one protruding member protrudes from the circumferential portion within the bore towards the rear end of the body portion; and contact between the contact member, inner sleeve and rotatable coupling nut is arranged to provide a ground path between the braided outer conductor layer and the rotatable coupling nut. the rotatable coupling nut is electrically conductive and is electrically coupled to the contact member; an outer surface of the circumferential portion of the contact member is at least partially disposed within the bore at the front end of the body portion; the at least one protruding member protrudes from the circumferential portion within the bore towards the rear end of the body portion; and contact between the contact member, inner sleeve and rotatable coupling nut is arranged to provide a ground path between the braided outer conductor layer and the rotatable coupling nut.