An electric connector is provided to ensure reliable termination of cable wires having different sizes. The electric connector can include a housing, a plurality of contacts, and a wire holder. The wire holder includes a wire support extension configured to be at least partially inserted into the housing. The wire support extension defines a plurality of wire receiving passages configured to arrange a plurality of first wires thereon and align the first wires with contact insert slots of the housing, respectively, when the wire support extension is inserted to the housing. The wire holder further includes a plurality of wire support ribs configured to centralize second wires smaller than the first wires.