This is a sole-source acquisition for 60 units of a flight-critical NSN part that requires government engineering source approval. Only sources already approved by the Government have been solicited, and the approval process for a new source would take too long to allow a contract award to be delayed. Unapproved sources may submit a proposal only if they include all required source-approval data or evidence that their request is already under evaluation. The Government intends to negotiate with a single source under FAR 6.302-1, but interested parties may express their capability for potential future competition. Drawings are not available, and the item is being acquired on a delivery FOB origin basis.