The part number for the SH68-50 is:
776784-01, 1 meter SH68-50
776784-02, 2 meter SH68-50
776784-05, 5 meter SH68-50
776784-10, 10 meter SH68-50
You can contact our Sales Department at info@ni.com or by phone at 512- 683 01 00. The delivery time for these cables is approximately 5 days.
Good luck with your application!