Atoplee 2pcs 0.3-3.2mm Electric Grinding Universal Multi Keyless Chuck Applicable scope: Suitable for grinding machine rotation tool 7.9 fine thread small soft spindle. It is suitable for holding all the shank diameter 0.3-3.2 mm accessories. Easy to use: Twist on the output shaft of a small soft shaft directly, then it can work. Exquisite workmanship: Heat treated & tempered high-carbon steel for durability. Suitable for grinding machine rotation tool 7.9 fine thread small soft spindle, such as Boach and Prokits, but Dremel can't match it.