The set comprises a Conical Metal Rotary File, which is great for working in tight spaces and around curves - areas where flat or half-round files may struggle - and a Cylindrical Metal Rotary File. This file is ideal for shaping and smoothing larger metal edges and surfaces quickly and efficiently. A tough Black Oxide coating reduces friction and heat build up on both files, ensuring work pieces aren’t burnt, while also extending the working life of each file. The ¼” Hex Shank provides a secure fitment for drill/drivers (not recommended for use with impact drivers).