One side is a rough file. One side is a fine diamond file. The thin side is a saw blade.
 The file has its origins in medieval woodworking tools.
 Specialized in grinding and smoothing surfaces.
 Sharpen a blade while camping or smooth out rough materials while crafting.
 It can grind soft metals such as copper and aluminum, as well as wood.
 Machining of non-heat treated rail is possible to some extent, but is not good for tool life.
 This function is assembled and used in BYTAL™_010_UTILITIES.
 800~899 is suitable for tools 2 and 3.