Im using the StarTech.com Under Desk CPU Mount. My desktop weighs about 44lbs. Im not going to say its the best mount, it could definitely better. However I honestly dont have any valid complaints.

https://www.amazon.com/gp/aw/d/B07L74Z87K/ref=ppx_yo_mob_b_track_package_o0_img?ie=UTF8&psc=1