It is a nice replacement after my other keyboard tray broke. I do not like that the mouse sits over number pad, but I do not use the number pad that much. Also. not a fan of the tray size, it does not fit my Microsoft natural 4000 keyboard. The keyboard hangs a little over it but again not enough to cause me to return it; the keyboard has feet on it that raise the keyboard up so it fits just about the ending bars of the keyboard tray.Ordered this for a very particular attorney, who poured over every detail of his keyboard tray and mousepad. He even asked for references before we swapped this in. We were looking for a keyboard tray with an elevated mousepad, as it is more ergonomic and comfortable for his wrist. Even when it arrived, this attorney was very skeptical. Once we swapped it in, he was an instant convert. Very nice tray, and very adjustable!this is fully adjustable with a tilt of tray. super comfy standing or sitting. can even adjust angles too. mouse tray slides up and down keyboard and a can be pushed over or to the right farther out from keyboard. it can go up or down side of keyboard. very sturdy not flimsy if you use normally. no keyboard is made to support body wait or pounding, i use in medical office daily sometimes i sit or stand, i love it. takes use to pulling out and tilting but totally worth it and got for $85vs $500 newDid not work correctly. It had to be returned.The mechanism is absolutely wonderful. You get a heavy-duty all-steel mechanism that slides out from under the desk and articulates from a sitting to standing position, just as advertised. I use it with a TreadDesk treadmill , which is built so you can roll a chair over it. So I can sit at my chair for 1/2 the day, roll it out of the way, raise the keyboard tray, tilt my monitors up and stand or walk until I get tired.That being said, the tray itself, especially the mouse tray, is flimsy and, I thought, unusable. You can't press down on it as you work, and the mouse tray is such a piece of junk that it's almost impossible to roll the mouse without it bouncing uncontrollably.Solution? I cut a piece of 5/8" plywood, cut it to 11 3/4" x 26" - painted it black and screwed it to the Fellowes mechanism instead of the flimsy tray. What I have now is a very solid work surface large enough for a Microsoft ergonomic keyboard and a vertical mouse, and it stays solid no matter what position I put it in. The tray tilts, too - a nice feature of the mechanism is that you can tilt the tray as you wish and lock it into position. I change the height and the tilt from time to time to relieve some stress on my hands and wrists, and that's a great thing considering how much time I spend at my desk each day.It's a shame that Fellowes can't built a tray worthy of the mechanism. But if you're willing to cut your own tray, it's a really great item.