Replace damaged or missing patio door rollers with this 1 inch plain back tandem roller assembly. Designed for a variety of sliding glass door manufacturers, it features two concave steel ball bearing wheels in a durable stamped steel housing. Each wheel has a 5/16 inch width with a steel inner race and ball bearings for smooth, quiet operation. The housing measures 1-1/32 inch tall, 11/16 inch wide, and 3-1/8 inch long, with a 1/4-20 threaded mounting hole on the back and an optional hole on top. Adjustable height allows precise alignment, though a mounting screw (1/4-20 inch) may need to be purchased separately. Ideal for DIY homeowners or contractors, this assembly restores effortless sliding door operation.