The Oster Finisher Model 59 Narrow blade is a replacement cutting assembly for close trimming and finishing work. Its nominal 1/125-inch / 0.2 mm cutting length leaves a very short finish, while the narrow blade format is intended for detail work in areas where access matters. It is designed for the Oster Finisher Model 59.

Oster manufactures the blade in the United States from high-carbon steel. The steel is hardened to Rockwell C 62–66 and receives a cryogenic treatment before the cutting surfaces are sharpened and finished. This is the narrow replacement identified by part number 76913-566-001.

The Finisher manual describes a two-screw blade mounting system. Unplug the trimmer before replacement, then align and center the cutting assembly as instructed in the manual. For ongoing care, brush away hair clippings and lubricate the blade with clipper oil, wiping away excess oil before continuing work.