The jig requires a router fitted with a 30mm guide bush and 12mm diameter long reach cutter. For most common sash mortice and dead locks with up to 3in deep mortices and a 7/8in or 1in face plate. Deeper mortices can be achieved with a suitable size of auger bit. Also suits face plate on a 1in mortice latch. NOTE. Use on doors 34 to 58mm thick