Royal Products Ultra-Precision ER Collet, ER-11, Round, 1/16" - 1/4" X 1/32" Runout is guaranteed to be 6 microns (0.0002") TIR or better Made from high-grade steels imported from Germany and are hardened for long life Includes 7 collets from 1/16" thru 1/4" by 1/32" steps Contain 16 slots to provide a large gripping range 1 year warranty against failure due to manufacturing defects