These are manufactured by German Stainless Steel and insulated by FDA approved nylon material.

FR:08-110A, U.S. Army Insulated Retractor /Parker-Langenbeck Retractor 8.5″ (21.5 cm), Set of two pieces.
Fig 1: 15 x 25 mm + 15 x 40 mm 

FR:08-110B, U.S. Army Insulated Retractor /Parker-Langenbeck Retractor 8.5″ (21.5 cm), Set of two pieces.
Fig 2: 15 x 30 mm + 15 x 45 mm