guide wire 1 as shown in fig3 the closure part 5 can be a connecting piece part and punch for the squeezer element 6 when the closure part 5 is screwed onto the collar 77 of the housing 7 in the direction of the arrows p 2 p 3 the squeezer element 6 is axially crushed as shown in fig4 thus the bore 64 of the squeezer element 6 closes and the guide wire 1 located in the bore 64 is firmly clamped in the squeezer element 6 the closure part 5 has a continuous nozzle stub 50 a with a continuous bore 54 from the distal end 52 to the proximal end 53 the distal end 52 of the nozzle stub 50 a of the closure part 5 is embodied as a luer lock connecting piece and has beads 59 protruding on the outside for interlocking with the catheter adapter 4 toward the proximal end the nozzle stub 50 b also has on the outside a detent bead 55 and is also surrounded by the coaxially embodied jacket 57 forming the annular chamber 56 a female thread 58 is embodied on the inside of the jacket 57 so that the closure part 5 can be guided with the annular chamber 56 over the collar 77 of the housing 7 and screwed onto it as shown in fig4 near the distal end 72 of the housing 7 on the inside of the collar 77 an annular bead 75 is embodied by way of which the closure part 5.