Sliding screen door corner assembly is used on jim walters doors and a variety of other manufacturers. it is an all-in-one corner and roller combination. it is made of stamped aluminum with an adjustment screw and center grooved spring activated high density polyethylene roller attached at the end of the bottom leg. the roller is 1 in. in diameter. the corner fits into the sliding screen door frame holding the bottom or top rails and the side stiles together.