Replace or repair broken or missing sliding door rollers with the Prime-Line D 1791 1-1/8 inch unique back tandem roller assembly. Designed for Milgard and a variety of other vinyl patio doors, it features concave steel ball bearing rollers in a durable stamped steel housing with a golden finish. The housing measures 3/4 inch wide and 1 inch tall for secure installation. Ideal for DIY homeowners and contractors, this assembly restores smooth, quiet sliding operation. Installation requires only a Phillips head screwdriver.