Our United States Navy Medical/Dental Patches are made from colorfast threads on heavy backing to keep their shape and good looks. Although most patches have an iron-on backing, we recommend that you sew them on for longer lasting results. These Patches make it clear that you or someone you know is proud to be associated with the Medical/Dental. These Patches measure approximately 3.5 inches. Your satisfaction is guaranteed, period. Usually ships within 4 - 7 business days.