3M Adjustable Keyboard Tray with Adjustable Keyboard and Mouse Platform, Price/EA

Is very heavy. Extends and pivots as expected and rises up to a good height. Side mouse tray is plastic, could be a little more substantial, but is still functional. I'd be careful sliding it in and out when storing underneath a desk.

I bought the bigger one. It is better than the small one.

This under desk keyboard tray gets 5 stars, but the attached mousepad only gets 3 stars.The keyboard tray fits together well, is easy to install and seems sturdy and adjustable to my liking. However, the mousepad only gets a 3 out of 5 rating.The pad itself is a bit small and only has a top rail. The bottom pad is ok, but comes with 6 3M adhesive pads that have the round tab at the bottom so you can remove the pad without damage to the mousepad? (?). The surface of the pad is a sturdy coating that is like a rough textured plastic that is very slick and smooth. The problem with this pad is that there is only a top rail, no side guards. If you happen to slide your hand off the keyboard reaching for the (wireless) mouse and bump it to the side, it slides off the extremely slick pad and ends up falling on the ground. Likewise if you push or twist the board too fast, the (wireless) mouse goes skittering off the right edge of the mousepad.

After many Christmas hints I purchased and installed this for my mom. I set it up as she requested without the mouse pad part attached so she can easily side it under her desk.

Modified a roll to desk that did not have a user friendly keyboard drawer. Added this hopefully my wife finds it comfortable

Took a chance on the upsell (on sale for under $150 when I did) on the knob adjust version (less up and down motion, but 14 track and full under desk stow), since it was one of the few that advertised an independently tilting mouse pad. Glad I did.Installation is easy IF you notice that you're actually supposed to set the track back farther than the directions initially tell you to. Nice thick metal for the track and adjusting arm, well greased track, keyboard tray itself is mostly plastic, but doesn't seem flimsy. Just enough spring throughout the system to keep my 10 tiny hammers from shaking the desk nearly as much, and seems to have a dampening effect re joint tiredness, without throwing off my typing rhythm noticeably (not speedy, but a two-handed typist who doesn't have to look at the keys... much). Turn knob is a little awkward vs other solutions I've seen, but works well, and if you just loosen it a touch it appears to let you adjust height without adjusting tilt. Drops low enough that it's actually convenient to type with keyboard under the desk, if you're into that. Good for standing desks.Front to back motion is smooth, side to side glide is key for getting the keyboard in the right position, since the keyboard tray itself isn't that big. Edit: there did seem to be a lean as some other reviewers mentioned, probably related to the weight of the mouse pad on whichever side you hang it from. Added some washers to the right, took care of it, but can understand frustration of other reviewers. Doesn't outweigh the massive positive of the independent mouse pad to me.Soaking of which, mouse pad is excellent. If mounted above the keyboard surface (1 inch or so), will let you slide it in tight to the keyboard (actually above the surface), even if the keyboard tray is tilted. You can also completely rotate the attachment point to have it even with the keyboard (tilt still adjusts independently), though that fixes it in place on the side of the tray. There's a clever semi-ratcheting lever that loosens / tightens for adjustments. Not sure which position I'll wind up using it in more.And all the padding is optional. Added the mouse pad, but skipped the keyboard pad and just used the included 3M double-sided sticky pads to lock it in place.Early review, but happy with my purchase, assuming it stays where I put it. I have small (30x26) custom mobile sit-stand desk so I can move around while working, and this effectively adds 10 to the front when I want it, which is awesome.