Prime-Line Products D 1754 Roller Assembly, 1-1/2 in. Tandem Wheels, Concave Edge, Steel Ball Bearings, Adjustable This steel ball bearing roller assembly is used to replace damaged or missing tandem roller assemblies in patio sliding glass doors 1-1/2 in., 3/4 in. wide housing, 1-1/32 in. housing height, 3-1/8 in. housing length Adjustable height with minimum collapsed height at 1-1/2 in. Steel housing construction with steel ball bearing wheels