I could not find anywhere an ad for a caddy for my Dell Optiplex 710. This item looks identical to the caddy in my Optiplex.  Sadly, it is just a tiny bit different, and that tiny bit prevents it from going in smoothly. So be sure your model number is listed before you order. (I found it possible to jam the caddy in, with hard drive in place, but then it became super difficult to pull out.)