Failed to load media. My versatile desk didn't have a keyboard tray and there wasn't enough legroom to buy a clip for an under-desk shelf. I bought these rails for a quick and inexpensive repair. I used a base chipboard shelf, cut it to size and attached the guides. The included small screws worked well. Rails are white. The size was accurate. All screws were present and the instruction manual was easy to understand. It glides well and stops automatically. My only flaw. I wish they said "Left and Right" or "Top/Bottom A, Top/Bottom B" and different colors (pure white, black, brown). Furniture.