This is a pre-solicitation notice for a one-time, Firm-Fixed Price requirement to procure Environmental Control Units (ECU) F100-60 in Green and Tan. The procurement is restricted to HDT Expeditionary Systems, Inc. as the only responsible source. The estimated quantity is 367 units, with inspection, acceptance, and FOB terms at origin. The solicitation will be issued electronically, and interested parties must monitor the designated website for amendments. No budget amount or performance location is specified.