Prime-Line B 714 Spring Tension Roller Assembly, 1-1/4 in. Outside Diameter, Concave Edge, Steel Ball Bearing This steel ball bearing roller assembly is used as a top and bottom roller to replace damaged or missing rollers on sliding screen doors Housing width is 2 in. x 3/8 in. thick with 1/4 in. wide wheel at 1-1/4 in. outside diameter Concave edge wheel (center grooved) Constructed of steel