DLMS™ Summary National Stock Number 1005-99-666-3583 National Stock Number (NSN) 1005-99-666-3583, or NIIN 996663583, (o-ring,weapon) has an unknown assigned date. This NSN does not replace any other NSNs. There are no manufacturer part numbers associated to this NSN. This part number has not been procured by the US Government in over 5 years. This NSN is assigned to Item Name Code (INC) 77777. This information was last updated on Jan 18, 2017.