double-ended, plain serrations, 3.0 mm & 4.0 mm wide, 7″ (17.5 cm) Bone File #64 is a double ended instrument that can be used in a variety of surgical procedures. This file features plain serrations and can be used to smooth out sharp edges on bone during surgery. In surgeries where such delicate tissue is involved such as nerves, vessels or even brain tissue it is imperative to keep sharp surfaces from causing tear injuries. Additionally this instrument is comprised of premium German operating-room grade stainless steel.