This Arcadia style roller assembly is used by Arcadia doors as well as a variety of other sliding patio door manufacturers. This is also currently a very popular design among patio door manufacturers in today's market place. It has a wire tension spring and comes with a 1 in. steel ball bearing roller, and fits onto the Prime-Line part B 569 corner insert. It is often used on the top as well as the bottom of the sliding screen door. Also look at Prime-Line parts B 515, B 541, B 714, B 736 and B 821 for similar spring tension rollers.