If you're skeptical about ordering from here, don't be! I recently purchased a second hard drive for my Studio 1749 and didn't realize I needed a caddy and adapter to install it.
Searched around only to find NewmodeUS that had one specifically marked for the 1749 and included the SATA adapter. I saw that they had Paypal and took the risk that maybe they were a good site.
Boy was I right. I ordered on a Friday afternoon and got a shipping label created just an hour later. After that, the tracking information said it had been dropped off at the end of the day on Friday.
The best part? I got the package on Monday morning all the way from CA to PA. Installed everything and it all worked! Plus, it looks a lot better than the stock caddy on the original drive!
Trust me, if you need something from NewmodeUS and only just heard about it, please trust them! They provide seriously incredible service for items that are ridiculously hard to find!
Hard drive caddy for DELL Studio 1745, 1747, 1749 (2nd HDD bay)