The National Institutes of Health (NIH) Clinical Center intends to award a sole-source, firm-fixed-price purchase order to RadSource Technologies for preventive maintenance and repair services on its RadSource X-Ray 3400 Blood Irradiator. This equipment is essential for irradiating blood components for transfusions and research, protecting vulnerable patients from transfusion-associated graft-versus-host disease. RadSource is the only known vendor capable of servicing this proprietary equipment while meeting regulatory and supplier qualification requirements. The Government will not issue a competitive solicitation, but interested parties may submit a capability statement demonstrating their ability to meet the requirements. Performance will take place at the NIH Clinical Center, where the irradiator is used by the Department of Transfusion Medicine.