Thermo-flex Catgut Sutures Completely sealed glass tube containing thermo-flex Catgut Sutures. The label states that they are Chromic, Medium Type C. They are non-boilable and measure around 54 inches, and are "Product 1445". Another label, while worn states that the date of manufacture is May 3 1943. Part of the Dr Diarmuid O'Driscoll Collection. 1925-1975