These are Trapezoidal lead screw nut manufactured by Ketterer comes with series of nuts such as Trapezoid thread nuts, Special thread nuts and Metric nuts. Each of the unit can come with different varying components such as Free cutting steel, Aluminium, Brass, Naval brass and Synthetic material. For this nut, it comes with pitches of 1 to 80mm per rotation and a number ot strts of about 1 to 12.