This sliding screen door roller assembly is made from a high density polyethylene housing with a 1 in. high density polyethylene ball bearing roller. The roller arm is adjustable with the adjusting screw on the end of the roller assembly. Most often found on Peachtree sliding screen doors, as well as a variety of other patio door manufacturers. Installation only requires the roller assembly to be inserted into the rectangle opening in the bottom of the door frame, then you slide it back until the installation holes align and install the screw.