This is a steel construction desktop converter. It is fairly heavy but also very sturdy. That being said, it works best for a laptop so that it does not become top-heavy when extended. It is freestanding and requires no installation.
The work station is adjustable and lockable; there is a lock tab (which you can see has some visible rub wear) which allows you to lift or lower the height with the side handle. The movement is quite smooth when you lift or lower, though I don't believe this is hydraulic. You can choose the height when you raise it, there are no set levels. There is a handle hole for easy transport. It is just one level, no second keyboard shelf.
It measures 15" deep x 22" wide. It can extend up to about 14" high. Weight is approximately 17 lbs. A keyboard and mouse are shown in one image for scale but are not included in this listing, which is JUST for the extendable workstation.