CKS series single one way ball bearings 2,low noise and low libration 3,High accuracy ,High speed 4,OEM Service Offered CKS series single one way ball bearings The CSK series is a one-way (clutch) ball bearing. One way Bearing Sprag/Clutch Freewheel and also called as Backstops. The one-way bearings are used in any application that requires one direction rotation, such as backstop, overrunning or ...