Inexpensive plastic. There's a lever that I have no idea what it does. I guess it will serve its purpose but I suggest you shop for a well-made metal unit. The bulk of the cost of this thing is in the "free shipping." Would not purchase again.

Fits perfect.

Very good purchase but there is a little problem with the mouse shelf. Once extended the shelf is not rigid enough so it bend a little as soon as you put your hand on the mouse. I believe there should be a review on this product to correct that weakness.

Purchased a new comp desk but didnt have a keyboard tray. This filled the need

Terrible design. Not enough room between desk and tray. Not enough tray space. Mouse area has no edges so it falls off the area constantly.