The Department of Defense, specifically the Department of the Navy through NAVSUP Weapon Systems Support, is seeking proposals for the procurement of three hydraulic modules, identified by NSN 7R-1680-015449008-H1 and reference number 42C42675A3. This procurement requires engineering source approval due to the flight-critical nature of the item, necessitating that only approved sources may submit proposals, and any new sources must undergo a qualification process as outlined by the Government engineering activity. Interested parties must provide comprehensive documentation as specified in the NAVSUP Source Approval Information Brochures, and proposals must be submitted within 45 days of this presolicitation notice, with all inquiries directed to Alyssa T. Thieu at alyssa.thieu@navy.mil or by phone at (215) 697-0169.