This includes the two main parts of the adjustable arm, thumbscrew, plastic washer, and rubber washer for the Atlas Extra Tall support.
This arm is the only difference between the Atlas Tall and the Atlas Standard or Atlas Short. If you have a Standard or Short, you can purchase this arm to convert it to a Tall.
NOTE: The holes where the arm attaches to the magnet are not threaded. The screw will self-tap the hole and create the threads when inserted for the first time.