This is a plain back patio door roller assembly with a 1-1/4 in. concave or grooved steel ball bearing roller. It is 9/16 in. wide with a 13/16 in. flare, 1 in. tall and 2-1/8 in. long. It is rear adjusting with a 10-32 threaded mounting hole on the back end. It is used by Acorn Doors and a variety of other manufacturers of patio doors. Color: Stainless Steel.