This is a Request for Proposal to replace the AHU system for the base gym, Building B1423, at Osan Air Base. The opportunity is strictly limited to contractors holding specific, listed MATOC contract numbers. A site visit is strongly encouraged and will be held at Osan Air Base in front of Building #600 on Thursday, April 7, 2026, at 0930 hours. The performance of all services will be at Osan Air Base. Key attachments include the Fair Opportunity Proposal Request, Statement of Work, and drawings.