This apparatus was typical of Holtzapffel's accessories. They were beautiful to look at, with polished brass, machine-turned steel surfaces and carefully fitted in well-crafted mahogany boxes. After 150 years of handling, they are still in excellent working condition. The series of gears were for fitting up the spiral mechanism to cut various length helical patterns on the workpiece. The two arms were fitted with one on the spiral apparatus spindle and the other on the lathe spindle, with their two ends joined by means of adjustable holes. Wave patterns of varying lengths and heights could be cut depending on the configuration of gears and adjustable arm eccentricities.