A disinfecting cap comprising a housing , a protrusion and a cap cover , the housing comprising a top wall , an essentially cylindrical sidewall forming a first cavity , and an open bottom end opposite the top wall formed by the cylindrical sidewall with an opening to the first cavity within the housing for receiving a hub of a female needleless connector or a male needleless connector , wherein the protrusion is positioned within the first cavity and comprises an inner surface , an outer surface and an end that is distal the top wall of the housing , the inner surface of the protrusion defining a second cavity , and wherein the outer surface of the protrusion and an inner surface of the essentially cylindrical sidewall define a gap therebetween, and the cap cover is dimensioned and positioned to cover at least a portion of the gap between the outer surface of the protrusion and the inner surface of the housing , characterized in that the cap cover comprises a body comprising a top surface , an opposite bottom surface, an exterior wall and an interior wall defining an opening , wherein at least a portion of the exterior wall of the cap cover is coupled or directly coupled to the inner surface of the housing and the cap cover interior wall is positioned proximal to, adjacent to, directly adjacent to or abuts the outer surface of the protrusion such that the cap cover is free to deflect downward into the gap between the outer surface of the protrusion and the inner surface of the housing upon insertion of a male connector into the disinfecting cap, or wherein at least a portion of the interior wall is coupled or directly coupled to the protrusion outer surface and/or protrusion end and the cap cover exterior wall is positioned proximal to, adjacent to, directly adjacent to or abuts the inner surface of the housing such that the cap cover is free to deflect downward into the gap between the outer surface of the protrusion and the inner surface of the housing upon insertion of a male connector into the disinfecting cap, wherein the cap cover comprises a resilient material, wherein upon detachment of the male connector from the cap, the cap cover returns to its original position. of the housing , the inner surface of the protrusion defining a second cavity , and wherein the outer surface of the protrusion and an inner surface of the essentially cylindrical sidewall define a gap therebetween, and the cap cover is dimensioned and positioned to cover at least a portion of the gap between the outer surface of the protrusion and the inner surface of the housing , characterized in that the cap cover comprises a body comprising a top surface , an opposite bottom surface, an exterior wall and an interior wall defining an opening , wherein at least a portion of the exterior wall of the cap cover is coupled or directly coupled to the inner surface of the housing and the cap cover interior wall is positioned proximal to, adjacent to, directly adjacent to or abuts the outer surface of the protrusion such that the cap cover is free to deflect downward into the gap between the outer surface of the protrusion and the inner surface of the housing upon insertion of a male connector into the disinfecting cap, or wherein at least a portion of the interior wall is coupled or directly coupled to the protrusion outer surface and/or protrusion end and the cap cover exterior wall is positioned proximal to, adjacent to, directly adjacent to or abuts the inner surface of the housing such that the cap cover is free to deflect downward into the gap between the outer surface of the protrusion and the inner surface of the housing upon insertion of a male connector into the disinfecting cap, wherein the cap cover comprises a resilient material, wherein upon detachment of the male connector from the cap, the cap cover returns to its original position. <EOS>