Options: Variations: ZAU497298 - Dimpled Base Insert 1 - $30.00 ZA497298 - Dimpled Base Insert for Festool PS 420 & PSB 420 Carvex Jigsaws Dimpled Base Insert for Festool PS 420 & PSB 420 Carvex Jigsaws Studded base with optimum sliding properties for wood or similar materials.