A high-density connector establishes electrical connections between insulated wires and other wires. The connector has terminals made of electrically conductive materials, for a plurality of insulated wires and a corresponding connector cap which has a round shape. The connector also has a base on which the terminals and cap are positioned. Each insulated wire has an insulation jacket. The connector includes front facing holes through which the insulated wires can be inserted. The terminals of the connector include a plurality of keyholes, each keyhole having a tail and a round portion that serves as the clearance hole for an insulated wire as it passes therethrough along with its insulation jacket. As the connector cap is rotated, it pushes the insulated wire placed in the round portion of the keyhole into the tail of the keyhole, which cuts into and removes the insulation jacket of the wire, thereby effecting an electrical connection between the electrical conductors of the wire and the terminals ofthe connector. The keyholes are adapted with particular tail widths to accommodate insulated wires of various gauge sizes. The connector can also effect electrical connection for a plurality of insulated wire.