Note that this is a wall mount arm, NOT a desk mount arm. It will not attach to a desk.
It was used for several years -- super functional and no issues -- and then moved to storage for a few years after a move. I no longer have a need for it.
Less than half the price of a new one. Price firm at $145. Cash or zelle only.
LX Sit-Stand Wall Arm
https://www.ergotron.com/en-us/products/product-details/45-353