This jig uses a set of interchangeable templates with a router will cut the mortise face plate recess for popular door locks for most common sash mortises dead locks with up to 3 inch deep mortises a 78 inch or 1 inch face plate deeper mortises can be achieved with a suitable size of auger bit fast clean accurate results on doors 34mm to 58mm thick even in hardwood steel plates body the jig requires a plunge router with a 80mm plunge fitted with a 30mm guide bush with 6mm spigot 12