10 Pieces of Senn Muller Retractor 20×6mm Blunt 7×9mm 6.25" Surgical Instruments: Senn Muller is a handheld, double-ended retractor used to retract primarily surface tissue. It is often used in plastic surgery, small bone and joint procedures, or thyroidectomy and dissection of neck tissue. This instrument has one angled, blunt end 20×6mm and, at the opposite end, facing the opposite direction has a three prong, rake tip. The prongs is 7×9mm blunt. This product has a straight. The overall length is 6-1/4 inches. Senn retractors are double ended retractors used in surgical procedures. One end is L shaped, and the other has three bent prongs. The pronged ends come in blunt tips. They are regularly used in hand and foot surgeries.