The Department of Defense, specifically the Department of the Navy through NAVSUP Weapon Systems Support, is seeking proposals for the procurement of two units of the air modulation valve (NSN 7R-1660-012027136-VH, REF NR 737047-4). This procurement is critical as the item is flight critical, and the government requires source approval prior to contract award due to the lack of adequate technical data for competitive solicitation. Interested vendors must provide comprehensive documentation as outlined in the NAVSUP Source Approval Information Brochures, and proposals must be submitted within 45 days of this presolicitation notice. For further inquiries, interested parties can contact Gina P. Sassane at (215) 697-2198 or via email at GINA.P.SASSANE.CIV@US.NAVY.MIL.