Prime-Line Roller Assembly, Number of Rollers: 1, Bearing Type: Ball, Roller Edge Type: Concave, Roller Diameter: 1-1/2 in, Nylon/Steel, C-Tab Mounting, Dimensions: 2-1/8 in L x 9/16 in W x 1-3/8 in H, Suitable for: Window Master and Other Patio Doors