This keyboard tray can tilt and move up and down, so you can adjust it for ergonomics, or even move it up enough to use any desk it fits on as a standing desk (the only issue with fit is the length of the track, and whether your desk is deep enough to mount that). I got it new and used it for only a couple months before I realized I needed to replace the very old desk I had put it on. In great shape, and I have all the hardware. These sell for $170 new, it's a solid, well-made product.
Here it is on the company website: https://www.mount-it.com/products/mount-it-adjustable-under-desk-keyboard-and-mouse-drawer-platform-with-ergonomic-wrist-rest-pad-mi-7139