Included with the case hardened steel tool post are three interchangeable steel holders designed to hold a 1/4" cutting tool, a 3/8" diameter boring tool and a Sherline cutoff tool. (Tools sold separately.) An optional holder for inserted carbide tips is also available as P/N 2295. Each holder has a knurled brass knob that allows you to easily adjust the height of the tool tip. Changing tools is simply a matter of releasing the locking screw, sliding out one tool holder, sliding in another and re-locking. If you find your jobs require a lot of tool changes, this timesaving accessory will make your projects that much more of a pleasure.