This base can be used to adapt your Carvex jigsaw to a Festool guide rail to get extremely straight cuts. When used with the Carvex, it can be attached to a guide rail to cut in either direction. It is also used in conjunction with the optional circle cutter (497 304) to cut arcs and circles. Also available as a set containing the Guide Rail Base Adapter and Circle Cutter (497 443). Works with all Festool Carvex Jigsaw models.