This is my first product review on Amazon (I did review one book in 2009, and you can find my own first novel, "The Coin of the Realm," on Amazon -- how's that for a shameless plug!), after buying many, many items here for many years. It's primarily because I want to counteract the negative comments about this product, virtually all of which reference adhesive failure, and also to let people know that it's really a great unit if you install it right.I've used a standard keyboard tray for a long, long time -- the kind with four feet that attach to the underside of your desk via screws, with a standard drawer glide -- and the design flaws finally got to me. Meaning, the unsteadiness, the unreliable locking utility, the inability to adjust height, angle, and position, the tendency for the screws to work out of the particle board desktop, etc., etc. So I researched online and settled on this model.The very design flaw that people reference in the comments on Amazon were to my mind a plus, because I realized the adhesive aspect would make installation a breeze. No way I would trust adhesive alone to hold up this entire assembly, though, and it's wrong of 3M to sell it that way. So don't assume you can trust it either. And 3M does include a pack of screws, so evidently someone there knows the truth.Here's what you do: You hook the front end (it also has adhesive on it) to the desktop, then press the back end to the desk underside for 30 seconds, and you have perfect positioning. Now you don't have to hold up a heavy assembly while lying on your back trying to make pencil marks for drill holes. Then, with the assembly firmly in place, you just take your drill and drill through the holes in the chassis into the desktop, put in 6-9 screws, and you have a rock-solid installation with the adhesive adding to the stability provided by the screws.The drawer itself is great, slides smoothly, and adjusted perfectly for me. (Note: it doesn't hide all the way under the desk; about 2 inches are left showing when you shove it in. That doesn't bother me at all, and in fact makes it easier to pull out, but I thought I should mention it.) My Apple extended keyboard and magic trackpad sit on the plain black tray perfectly, there's no wobbling or unsteadiness, and all-in-all it's a very professional set up. They include a bunch of adhesive strips in case you want to affix your keyboard permanently to the surface -- I didn't use them or even try them. My keyboard just sits there and doesn't move.I've run my own consulting business (DubinMarketing dot com) out of my home office for 16 years, and my time and productivity are critical. Hard to believe something so minor could make such a difference. What an improvement, and how I wish I'd made the change many years ago.A word about Amazon. I got this via an open-box warehouse deal for $80, including shipping. When it arrived, the wrist pad was missing. I called Amazon, reached a great gal named Christy, and she took care of the situation fast and authoritatively. Together we located a replacement 3M wrist pad on the site -- for all I know it's a better one than the missing one, since it's a top-of-the-line gel unit that alone costs almost $30 -- and she sent it to me for $0. Wow.Hope this helps your buying decision!As seen on the pictures, the install was pretty straightforward. Only thing you really need to do is follow the instructions to a T, particularly when setting up the velcro union on the railing BEFORE you put the rail in place. Other than that really easy.I did not use the stricker for the gel pad, it holds on perfectly still without them while you rest your wrists on it.The mouse pad has to be stuck though, as it needs to be still on the surface.Adjusting the height was pretty easy too, just turn the knob until you feel there is enough play to move the base up an down and adjust as needed. Don't lose the knob too much otherwise you will lack control.Finally, as seen on the second picture, the base does not go all the way in, you have a couple inches that protrude farther than the end of the table. Not a problem for my particular instance, I was able to store the keyboard and use my desk space with little problem.I will update later on if the velcro has any issues (as there are reports for this around), but I think doing things in the right order should prevent this as the velcro is really strong and once placed it feels pretty sturdy.-----------------UPDATE: As noted by others, the Velcro failed. Thankfully the unit held up on the front lip or it would have broken one of my nicest guitars. I ended up removing all the velcro pieces and using two of the included screws on the tail end. I will update further if that fails, but it seems it will hold fine for a good while.I purchased the tool-free version with mobility in mind. I wanted to be able to move the keyboard tray since I have more than one setup. While this may not apply to most people, the review might be useful.The keyboard tray is very well built. It is strong, doesn't bounce or move with regular use. It can be moved up or down, tilt up or down and rotate left to right. So you will be able to find a position to meet your needs. Based on these features, I would recommend it.However, as others have pointed out, the velcro is not strong. You have to be gentle when you are adjusting or moving the tray or it will come off. You will want to use the screws it on to the desk, which defeats the purpose of tool-free installation. Since my goal was to be able to move it relatively easily, I purchased neodymium magnets and replaced the velcro with the magnets. This worked for me. The connection is much stronger and will not dislodge with usage. I have to purposely separate it now.Overall, I would recommend not getting the tool-free version because you would need a tool to install it. There are limited cases where it comes in handy such as my case. However in most cases I would recommend one with more stable connection to the desk.Consider before install because you can only use the supplied Command Strips one time. I have carpal tunnel in my right wrist, which is why I purchased this keyboard tray. It's nice and works great and was easy to install. Although I was missing one of the Command Strips for the wrist support cushion, I was able to manage by cutting one of them in two. Things you want to consider before you install it: If you install in "on-center" with your desk, it will be offset due to the space taken up by your mouse. Therefore, I re-centered mine more to the right side of my desk (I'm right handed), this way the keyboard would be centered to my monitor vs me having to sit slightly to the left of my keyboard tray and monitor. I hope this makes sense and helps someone out, because if you in stall in then want to move it, you will not be able to reuse the Command Strips. I uninstalled my keyboard tray and ruined my Command Strips, I ended up running up to the hardware and grabbed some Scott's double sided take to replace the Command Strips and I worked out just fine. Hopefully my review will save you some time and hassle.I don't believe I have seen anything so ridiculous. The keyboard base is too heavy for the runners,and it's massive. The instructions are useless. It's supposed to rotate 360 degrees and mine won't move. The keyboard base tilt is no use whatsoever. Must have been designed by someone who has had too much to drink.Very good quality and easy to install. However, there is a great weakness in the design if you plan to install it without using any screw. The rails on which the tray slides is attached to the desk through a clamp in the front and a plastic part at the back. The problem is with the plastic part, which has two halves. One of the halves is stuck to the underside of the desk via the 3M adhesive pads, and the other half is attached to the end of the rail. The two halves "mate" through matching "teeth" found on both halves. This is the weak link of the whole thing. When the tray is retracted under the desk, the weight would cause the tail end of the rail to detach from the half that is stuck to the desk. As a result, I can't retract the tray when I'm done for the day. It is a minor inconvenience, but a design flaw that should not have existed. I would give it a 5 star rating if I were to install it with screws because it is an excellent product, but one of the important selling points to me is tool-free installation (and removal). As it is, I would have given a two star rating, except for the fact that it is indeed very easy to install without needing to drill the desk and that it can be easily removed when my contract is up. I have zero problem using it in the "deployed" position. Look for another option if installing without screws and retracting the tray are important to you.The clamp model (one that does not require screwing to the desk) does not fit the corner maker. In any case, the product seems excellent so far, it glides smoothly, is very adjustable, and feels very sturdy. One thing to note is that if your desk is not super high, the tray will of course reduce the clearance to your legs. My knees now regularly bump into the tray, but I would rather that than type on my desk - so I don't mind it. Bought a second one!edit: over time the adhesive tapes have actually shifted and now the tray is misaligned. The first one actually kept falling off over and over again after the adhesive shifted. I had thought that it was just a lemon - so I ripped out the adhesive and replaced it with 3m VHB tape - which has held up like a champ for the last week or so. The second one that I bought I made sure to check that the adhesive was aligned when I mounted it under the desk. But over the course of less than a week, I noticed that the tray now wobbles and I see that the tape has been peeling and shifting from its original position. I will have to also replace this with VHB tape, as the adhesive for the velcro is not up to the task (the command strips sticking the velcro to the desk have been fine so far).edit: VHB tape stayed in place for 2+ weeks, but eventually fell off too like the factory velcro. Just going to screw it into place.J'ai une déchirure du tendon sus-épineux et je fais de la transcription médicale toute la journée sur le clavier. Avant d'acheter ce produit, chaque fois que je le levais le bras pour utiliser la souris, j'avais une douleur qui ne faisait que s'accentuer durant la journée. Depuis que j'ai ce porte-clavier, j'ai beaucoup moins mal au bras et la qualité et la facilité d'installation du produit valent le prix qu'il coûte. J'aurais dû acheter ce produit il y a plusieurs années.... La seule anicroche est qu'il faut tout le temps ajuster la souris pour qu'elle soit dans l'écran, vu que le porte-clavier est en pente pour mon confort, mais au moins, je n'ai pas mal au bras toute la journée.I'm not sure how everyone else is doing so well with this - mine failed miserably! Within 30 min. the sticky pads that adhere to the underside of the desk came unstuck and the entire thing went crashing to the floor. First the keyboard tray became unconnected from the part that sticks to the desk, the plastic "teeth" connection is incredibly weak. I re-attached it numerous times but within half an hour, even that wouldn't stay put. All hope was lost and the sticky lost its stick. I'm relieved I wasn't sitting there at the time or my feet and calves would have been hurt.I'm currently debating whether to return it for a refund or try to figure out how to Jerry-rig it to stay up in some other way. I would prefer not to have to duct tape a keyboard tray up. I have a glass desk so the screws are not an option. I was very excited to see this 'no tool install' and thought it was the perfect solution to my keyboard issues. Nope. FAIL.