They are really 100% brand new with high quality 50pcs RJ45 CAT5E CAT6 Pass Through Open End 8P8C Modular Plug LAN Network Connector.
RJ45 design allows the wires to pass through the connector so the twists in each pair can be pulled closer to the contacts than conventional plug.
Maintaining the twists to the point of termination significantly decreases crosstalk and markedly increases performance
