Andersen Gliding Patio Door Tandem Roller is engineered to provide smooth and reliable operation for Andersen 100, 200, and 400 Series Gliding Patio Doors. This tandem roller assembly features dual ball-bearing rollers that enhance durability and performance, ensuring your door glides effortlessly. It includes self-contained leveling adjusters to maintain proper alignment, making it an i part for patio doors manufactured from 1982 to the present. This roller also replaces older parts from 1964 to 1982. For optimal function, it is to replace both rollers when performing maintenance. Model Number: 1997061