Designed with perfect geometric shape. Provides maximum practicality during work thanks to the tightening by rotation. Eliminates the presence of the key and often its loss during operation and frequent change of working accessories. Suitable for standard drills, based on dimensions: 1/2 "x 20 UNF. With a capacity of 13 mm and stable work with drills up to 750 W. Resistant to work and precise in use.