Works just fine with my ProForm 400 treadmill. I've enough room for my phone, keyboard, two monitors, various desktop detritus, and an elbow or two. It's sturdy. Thought I'd have to add a brace per another reviewer's recommendation, but so far, so good. Assembly: Did it solo, and doggone, if I ever build one again, I'll borrow someone's drill. There are a boatload of screws to drive into the plastic desktop! Like, oh, seemed like 379... but probably 50. I'm a lousy driver-of-screws so it took me three hours and some creative cursing to put it together. A competent person with a power driver could slam this together in less than an hour. Instructions are well-written. I like the paper rack accessory. Not wild about the cup holders sticking out over the edge. If you're rowdy like I am, at some point you're going to stand up under one and knock your cuppa water out of its holder. Brr. A nice product, which will probably come down in price once treadmill desks become more mainstream.