A medical adapter having both a needleless valve and a sharpened cannula is used to connect or adapt pierceable septa containers or other devices having different sizes to needleless connection. The adapter includes a needleless site at one end and a sharpened cannula at the other end protected by spring arms. These arms include claws at their distal ends to grasp the neck of the pierceable septum device to which the sharpened cannula is to be inserted. The claws include sharpened points for gripping the device. The arms are located on either side of the adapter body and are connected to the body through springs. Handles are also included on the arms for use by the operator to separate the arms against the spring forces during engagement of the adapter with the septum. In one case, the handles include finger grips located above the springs for pressing the handles inward to open the arms and claws and in another case, the handles are located closer to the distal ends of the arms for pulling the arms outward. The adapter in one case comprises only three parts for reduced materials and manufacturing expense.