roller screw jack feature: 1.positioning precision, safely self-locking 2.more precision than trapezoidal screw jack roller screw jack description:1.Model: RNK-0.5T,1T,2T,3T,5T,10T,15T,20T2.Configuration: worm and worm gear,bearing,housing and ball screw3.Ball screw jack assemblies use small balls to roll between the nut and screw jack. This creates significantly less friction than lead screw ...