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 PrimeLine 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 PrimeLine parts B 515, B 541, B 714, B 736 and B 821 for similar spring tension rollers