The Department of Defense, specifically the Department of the Navy through NAVSUP Weapon Systems Support MECH, is seeking to procure 80 units of hydrophone assembly and similar replacement parts under a presolicitation notice. These parts require engineering source approval to ensure quality, necessitating that acquisition or repair be conducted only from approved sources with unique design capabilities and manufacturing knowledge. The procurement is critical for maintaining the operational integrity of underwater sound equipment, and interested parties must express their interest and capability within 45 days of the notice, with contact details for inquiries provided by Heather R. Jones at heather.jones2@navy.mil.