This is a non-competitive, sole-source procurement for two unstable parts that are pending major design changes, which will render the current configuration obsolete. The item is flight-critical and requires Government source approval prior to award; only previously approved sources have been solicited. The Government intends to negotiate with only one source, but all responsible sources may submit capability statements. Proposals received within 45 days of the synopsis publication will be considered. The performance location is not specified, and no budget information is provided.