The nozzle (1) has an oblong hollow cylindrical body opened at an end and closed at an external end. A side slit extends from the open end toward the external closed end and terminates in a side opening whose dimension is greater than width of the slit. The opening is formed with a passage in a center portion to introduce a guide wire into the body. Shape and dimension of the nozzle are formed such that the wire cannot penetrate in a part of the nozzle beyond the opening between the opening and the closed end when the wire is inserted in the nozzle by the opening of the open end. The guide wire is introduced into the body in a relative sliding motion by pulling the nozzle and the wire, where a free end of the wire is intended to arise from the nozzle by the opening. An independent claim is also included for a ritleng system.
