There are two insert (ms21209f1-15l)included with standoff
A standoff that must have a threaded end(s) or be internally threaded its full length. For items having external threads on both ends, see stud (as modified). For items with an outside contour that is the same for the entire length, are flat on top and bottom, having internal threads its full length, and the length does not exceed twice the width across the flats or outside diameter, see nut (as modified); use maximum dimensions(s) for compliance.
NSN 6105-00-827-0616
NSN 5950-00-518-4645
NSN 5990-01-256-8441
NSN 6135-01-167-7604
NSN 5999-01-483-6313
NSN 6240-01-600-1092
NSN 5960-01-029-5637
NSN 5985-00-111-4539
NSN 5855-00-560-0110
NSN 6135-01-446-6010
NSN 6110-01-503-3266
NSN 6650-00-518-5194