NSN 0R-2840-017139884-B8, REF NR 5145T41P02, QTY 841 EA, DELIVERY FOB ORIGIN. The Government physically does not have in its possession sufficient, accurate, or legible data to purchase this part/cont... NSN 0R-2840-017139884-B8, REF NR 5145T41P02, QTY 841 EA, DELIVERY FOB ORIGIN. The Government physically does not have in its possession sufficient, accurate, or legible data to purchase this part/contract repair from other than the current source(s). THIS IS A CRITICAL SAFETY ITEM (CSI).