Extralink 4P+6P+8P crimper with lock The Extralink crimper is a tool intended for crimping connectors in twisted-pair cables. It can be used to crimp three types of connectors: RJ-45, RJ-12 and RJ-11, both shielded and unshielded. Handle lock The crimper is equipped with a handle lock that prevents the clamps from opening until it is released. Built-in blades are used to cut the cable or notch its outer sheath.