600 Lb. capacity per pair. Features Delrin wheels and flexible trunnion. Offset 7-1/2 In. bolt (with 5-1/2 In. thread) adjusts door vertically (5-1/2 In.) and laterally (1 In.) from inside building. Includes 2 star washers, 2 hex nuts, 2 flange nuts. Weather Guard protection. National catalog model No. 5310.