ller assembly features a steel constructed roller and a spring loaded design. It comes affixed to an adjustable steel housing with a top adjusting screw. This roller is used by Bay-Mills and other door manufacturers.From the ManufacturerThis roller assembly features a steel constructed roller and a spring loaded design. It comes affixed to an adjustable steel housing with a top adjusting screw. This roller is used by Bay-Mills and other door manufacturers. This product adds a great value | Product is highly durable and very easy to use | This product is manufactured in China | Spring Loaded Design | Steel Housing with Top Adjusting Screw | Used by Bay-Mills and other door manufacturers