685 is a 5 mm Ball Bearing that can be used in many rotary and factory automation applications. The 685 Miniature Ball Bearings is an open style bearing. The 685ZZ ball bearing has a single row raceway and it is shielded on each side. The 685 5 mm Ball Bearing Inner Dimension 5mm,Outer Dimension 11mm,Width 3mm is an open style ball bearing designed for high rotational speeds and high dynamic loads.