The Department of Defense, specifically the Department of the Navy through NAVSUP Weapon Systems Support, is soliciting quotes for the procurement of air heat exchangers, identified by NSN 7RH 1660 014648900, with an increased quantity requirement from 1 to 4 units. These heat exchangers are critical components used in aircraft air conditioning, heating, and pressurizing systems, underscoring their importance in maintaining operational readiness and comfort in military aircraft. Interested vendors must submit their proposals via email to Joshua Seltzer by the specified due date, and those not already approved as sources must include additional documentation as outlined in the NAVSUP WSS Source Approval Brochure. For further inquiries, potential bidders can contact Joshua Seltzer at 215-697-2849 or via email at joshua.j.seltzer.civ@us.navy.mil.