Replace or repair broken or missing sliding door rollers with the Prime-Line D 1739 tandem roller assembly, compatible with a variety of patio door brands. Featuring 1-1/4 inch concave plastic ball bearing rollers in a durable stamped steel housing with a yellow zinc finish, this assembly delivers smooth, quiet operation and long-lasting performance. It includes a 1/4-20 mounting hole on the back and an optional #10/32 threaded hole on top for versatile installation. Perfect for DIY homeowners and contractors, installation is easy with a standard Phillips head screwdriver. Restore your sliding doors to effortless operation with this strong, reliable roller assembly.