Heritage Auction Galleries is selling this flag: 86" x 68". This red wool bunting flag has "United States Sanitary Commission" in sewn white cotton letters approximately 2" wide and 10" high. The hoist is reinforced with 0.75" wide white cotton bunting. This historic Sanitary Commission flag is the only known surviving example. It has been professionally conserved, framed, and is in excellent condition. From the Collection of the American Red Cross.
The link below will bring you to the listing.
Ed