Laquon Ergonomic Mesh Drafting Chair Footrest Ring Spacer

I bought the chair from Wayfair. It's a pretty decent chair but It was annoying having to constantly readjust the footrest ring from being pushed down. It has a handle to try and lock it in place but it seems to keep moving down, especially if you use the footrest to push yourself back into the chair more. I designed this simple spacer to take up the space so it can not move down anymore. 

You can adjust how tall you want to print this by extruding the z axis. I would suggest that you measure where you like to keep the foot rest and then just size it accordingly. You will have to separate the chair from the pneumatic cylinder to instal.