A Luer access device, comprising: a body having an outer surface; an opening formed in the outer surface and configured to receive a needleless connector; a soft septum disposed in the opening and having a slit for receiving the needleless connector; a set of threads on the outer surface and positioned proximate to the opening, a portion of the body being adjacent the set of threads; and a retention feature disposed on the portion of the body adjacent the set of threads, wherein the retention feature is positioned to contact a portion of a complimentary set of threads on the needleless connector when threadedly coupled to the set of threads and provide increased resistance to unintentional disengagement of the threaded devices and a tactile feedback to a user of a tightened connection between the Luer access device and the needleless connector, characterized in that the retention feature comprises a protrusion comprising a forward ramped surface and a rearward ramped surface opposite the forward ramped surface, wherein the forward ramped surface and the rearward ramped surface are tapered along an axis that extends outwardly from the body, wherein the rearward ramped surface is tapered at a greater angle than the forward ramped surface is tapered, wherein the forward and rearward ramped surfaces (352, 354) are spaced apart by an outermost surface of the retention feature, wherein the forward ramped surface is configured such that a force to pass the complimentary set of threads over the forward ramped surface gradually increases as the complimentary set of threads travels over the forward ramped surface. a body having an outer surface; an opening formed in the outer surface and configured to receive a needleless connector; a soft septum disposed in the opening and having a slit for receiving the needleless connector; a set of threads on the outer surface and positioned proximate to the opening, a portion of the body being adjacent the set of threads; and a retention feature disposed on the portion of the body adjacent the set of threads, wherein the retention feature is positioned to contact a portion of a complimentary set of threads on the needleless connector when threadedly coupled to the set of threads and provide increased resistance to unintentional disengagement of the threaded devices and a tactile feedback to a user of a tightened connection between the Luer access device and the needleless connector, characterized in that the retention feature comprises a protrusion comprising a forward ramped surface and a rearward ramped surface opposite the forward ramped surface, wherein the forward ramped surface and the rearward ramped surface are tapered along an axis that extends outwardly from the body, wherein the rearward ramped surface is tapered at a greater angle than the forward ramped surface is tapered, wherein the forward and rearward ramped surfaces (352, 354) are spaced apart by an outermost surface of the retention feature, wherein the forward ramped surface is configured such that a force to pass the complimentary set of threads over the forward ramped surface gradually increases as the complimentary set of threads travels over the forward ramped surface.