Abstract: Disclosed is a stopper for use with containers to provide needleless access to the container with a cannula having a blunt penetrating tip. Also disclosed is a system comprising the stopper, container and cannula. The stopper includes a disc having an upper face and a lower face, and a plug extending from the disc into the container. Also included is a diaphragm, defined by a target region in the upper face and a cross channel in the disc for controlling the force needed to penetrate the stopper with the cannula. The plug includes a first inward surface for guiding the cannula and a second inward surface for engaging the cannula to minimize wetting of the outside of the cannula. In a preferred embodiment, the first surface extends down from the cross channel on the lower side of the disc, radially outwardly to a maximum diameter and the second inwardly facing surface extends down from the first surface radially inwardly to a minimum diameter to form the cannula seal.