The 6" Dial-A-Width Dado set performs like a stacked dado, but Freud has replaced the shims with a patented dial system and with the exclusive Dial hub. This ensures accurate adjustments. Each "click" of the dial adjusts the blade by .004". The Dial-A-Width Dado set is easy to use and very precise. For the serious woodworker, there's nothing better. Adjusts in .004" increments. Maximum 29/32" cut width. Adjusts easily to right or left operating machines. Set includes 2 outside blades, 5 chippers, wrench and carrying case. Does not need shims.