... : drill for a style, level 3 rolling bearing and two way thrust, steel ball lock, center, suitable for high speed often.2 ... no drill style, level 3 rolling bearing, a thrust, steel ball lock, deduces the center. Suitable for high speed.3.And ... , level 2 rolling bearing, a thrust, small shaft sliding, steel ball lock, suitable for high speed.4.Bit bearing no seal ...