Full disclosure, I've only had this installed for about 10 minutes now. So far, they work and seem to be a significant improvement to the clamp option.I had been using a keyboard tray that clamped onto the desk. After years of that swimming and shifting each time the tray was pulled out or pushed in, I finally decided that (with a wooden desk) I should invest in something more permanent. I settled on the 12-inch length because that is how long my keyboard tray is. I also settled on these…