Patented and unique, Freud's Entry and Interior Door System lets woodworkers build doors with true mortise and tenon construction for rock-solid joints that last a lifetime. These sets include rail and stile bits that are perfectly matched to produce perfect joints out of the box. Or remove the top section of the rail bit to produce long tenons of any length for the strongest possible joints. The 99-267, 99-268 and 99-269 sets can be used to mill 1-3/8" or 1-3/4" thick doors. For even thicker material, choose the 99-277 set for 2" or 2-1/4" thick doors. Use with table-mounted routers to mill hardwood or softwood door parts.