Linear Guide Rail Set: This listing includes supported linear rails (SBR20-300/600/1000mm), comprising 6 supported rails and 12 SBR20UU bearing blocks. Also included are 3 RM1605-350/650/1050mm-C7 ballscrews (3 screws, 3 ball nuts and 3 end-machined sections), 3 sets of BK/BF12 supports (with locknuts and circlips) and 3 flexible couplings. Experience smooth movement without deflection, minimal wear and low noise.