Prime-Line Roller and Axle Kit, Number of Rollers: 2, Bearing Type: Ball, Roller Edge Type: Concave, Roller Width: 5/16 in, Roller Diameter: 1/4 in ID x 1-1/4 in OD, Steel, Gold/Zinc, Suitable for: Sliding Patio Glass Doors, Includes: (2) Assorted Axles