Ergotech Heavy Duty Freedom Arm, Includes Single Aluminum Heavy Duty Articulating Arm, 20-30.8 lbs. Weight Capacity, Suitable for Monitors up to 27 inches, VESA Compatible 75×75, 100×100, Silver

I've used several types of monitor arms at different employers and bought 2 of these for myself at home. I can't say enough about how impressed I am with the sturdiness of the setup and the installation simplicity. It took all of 10 minutes to be up and running. My monitor weighs 20 lbs. and the arm didn't need any adjustment to support it perfectly. I worried it would be complicated when I saw all the hardware packages but most of it is extra because it supports 8 monitor configurations.This arm's clamp base was bigger than I expected (about 6 1/2" wide and x 5" deep) but that might be necessarily typical of an arm with the capacity to hold over 30 lbs. The padding on the clamp and the surface area it spreads the stress across left me confident it wouldn't mar my custom hardwood desktop. In fact the size might be appreciated if you've got a cheap particleboard desktop. A heavy monitor cantilevered out from a smaller base might twist or warp a cheap desk if the base is too small.The base reaches 3" under the desk, 4" on top, and needs 1" between the desk and any wall or partition. The monitor bracket & arm require 4" behind the monitor so if your desk is against a wall the back of your monitor can be as close as 4" from the wall before the arm will touch the wall.One reviewer said the clamp doesn't support desktop thickness greater than 1 1/4" but I guess he didn't see that the clamp can be widened by unscrewing it from the bracket and re-attaching it on a lower set of holes. In any case it does support the full advertised thickness. It just comes pre-configured for a 1 1/4 max thickness.The range of motion lets me switch my 27" monitor from landscape to portrait quick and easy and the monitor stays put with no effort.I'm very happy with this stand, especially given it's price-point is at the bottom end for its capacity and features.

I needed a monitor arm long enough to reach across a three-foot deep craft desk, and this was the only one that reached far enough. At first, I had difficulty getting my monitor into the right position. I have a 24" Asus monitor, which is below the minimum weight of 20 lbs, but with the tension spring on the lowest setting, the monitor arm base about halfway down the pole, and some strong arm adjustment, I've managed to get it to the proper ergonomic height. The clamp that holds the pole to the desk is pretty stout and it did do some damage to the finish of my desk, but I'm not terrible concerned about that. I just want it to be secure. Keep in mind that the clamp needs about three inches of horizontal space to clamp onto, and no more than an inch and a quarter thick. There are some screws on the clamp that keep it from being totally flush to my desk, but only because my desktop is at the maximum thickness. A thinner desktop would not have the same problem.With all that said, this thing is STURDY. When I said I had to strong arm it in place, I meant it. The springs are really tight, even at the lowest tension setting, but now that it's in place, it's not too difficult to move the monitor arm side to side, or to adjust the tilt and rotation of the monitor itself. All in all, I am extremely happy with this purchase, and I feel like it will last a long time just looking at the construction and materials used.

I ordered the Ergotech Freedom Arm HD (FDM-HD-S01) from Amazon, it arrived before the expected date (the Amazon order tracking was still showing it in route, even after it had arrived).At first I thought Amazon had shipped the wrong arm because the product# on the box was different (FDM-MAC-S01-VESA), I had wanted the "HD" (heavy duty) model because I was mounting my 20lbs+ iMac 21.5 on it. I went to the Ergotech website and the specs on the FDM-MAC-S01-VESA where the same as the HD model, and had the same capacity for 20lbs to 30lbs of weight. I called Ergotech, they confirmed that it was the same product.While on the phone with the Ergotech guy, I asked him about the thru desk grommet mount, (the arm I received only came with the desk clamp) a reviewer had said it came with the grommet mount. It does not come with the grommet mount, you have to purchase that separately (FDM-GROM-G, for $26.99). According to the Ergotech guy, the grommet mount also comes with it's own vertical pole, so you will end up having 2-poles (interesting way to sell it).Installation had a few minor snags. My "U" shaped desk is so close to the wall, and too hard to move, that I had to take the clamp off the pole mount and re-attach it under the desk, this wasn't to hard, only 4 screws, was a little awkward under the desk.Another snag was my 1" thick desk seemed to be just the wrong thickness for the clamp, when I re-attached the clamp to the mount in the widest position, the screw clamp could not reach the bottom the desk. When I tried to move the clamp to the tighter position, the bottom of the desk was right at the screw holes, so there was no real room for the clamps metal frame. My solution was to leave the clamp in the widest position, and place a sturdy piece of 1/2" plywood as a spacer, this worked well, the arm attachment is totally firm. (I recommend using a hard piece of plywood, so it cannot split or compress)Be careful with the two tiny allen screws that come with the hardware, one dropped on floor when I was unboxing, didn't even see it, had to go back and look for it.Everything else was fairly straight forward, it does help to have someone help you, it can be somewhat unwieldy placing the arm on the monitor/computer, and placing the whole thing on the support pole is easier with an extra set of hands.I attached the Freedom Arm's VESA mount to a stand mounted VESA adapter (not an Ergotech product) for my 21.5 iMac, It works pretty good, the iMac stand does get in the way somewhat but not too bad. The arm works good, seems very sturdy. I think the arm would work even be better on a desk that is not against a wall, you would get a better range of movement. Also if you use a wireless system (keyboard, etc) you will find it easier to move it into position. All in all I am satisfied with the arm, it is very convenient to position your monitor/computer where you want it. I will update my review after I have been using it awhile.12/11/19: The Ergotech arm still works good. I am now using it to hold my 2019, 27" iMac, which it supports with no problem.