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 5945-00-900-6787
NSN 5965-01-529-4417
NSN 5960-01-237-8995
NSN 5925-01-017-1036
NSN 6220-01-361-3483
NSN 5965-01-204-1423
NSN 5855-01-334-6594
NSN 6135-01-122-4448
NSN 5915-00-982-2859
NSN 5975-01-071-4521
NSN 6320-01-513-9166
NSN 6685-00-762-8027