This is a solicitation for 200 units of a flight-critical spare part, delivered FOB Origin. The procurement is restricted to previously government-approved sources due to the critical nature of the item and insufficient technical data for open competition. Companies that are not already approved sources must submit a comprehensive source approval package with their proposal, following the specific NAVSUP WSS brochures. The government warns that the source approval process is lengthy and typically cannot delay an award, meaning unapproved sources are at a significant disadvantage. Offers from unapproved sources that do not include the complete required approval data will not be considered for award.