●Sizes: 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 3.175mm (1/8") ●Outer Diameter (D1): 11.5 mm, Height (L): 18 mm, Hole Diameter (D2): 1-7 mm, Accuracy: <0.012, Height: About 0.68 inches, Runout Tolerance: 0.01 mm (0.006 inches) ●The collet uses less pressure on the work than a nail, so it can be firmly fixed ●The holes are processed to fit the shape of the work; insert the work into a tube (collet) with a radial cut from the center and tighten it from the outside by tapering or other methods ●It is also used to chuck an end mill for touring, and in that case, it is provided to match the end mill shank