Rat tails aren't the same thing as round files, so I'm not sure if that's really what you want... or what you want it for. I have round files from little needle files up to big 12 or 14" aggressive ones. For bows, I mainly use them on string grooves, and just use a 4" Nicholson, then a smooth chainsaw file to remove file marks from the 4", then wrap 400 grit sandpaper around it. I get most of my files on ebay nowadays, but I'm always looking for good deals on files. Can't have too many, or too big a variety of files.