The Parallel Guide Extensions must be used in conjunction with the Parallel Guides and any length Festool FS/2 Guide Rail (Parallel Guides & Guide Rails sold separately).
The best value is purchasing the Parallel Guides & Parallel Guide Extensions as a Set (#203160).
The Parallel Guide System greatly enhances the capability of the Festool Guide Rail System by providing a faster, easier, smarter way to create consistent rip cuts. The Parallel Guide Extensions connect to the Parallel Guide (495717), enabling narrow rip cuts from 1mm to 195mm (1/16 in to 7-11/16 in).