Yep, you can put the Clip in a padded envelope (you can buy a padded envelope all over–UPS, the post office, drugstores, office supply stores (Target, Staples, Walgreens, etc.)), and then I’d wrap the Clip in some bubble wrap or padding inside the envelope as well, to protect it.
Or, perhaps better, just mail it in a small box with some padding on the box, again to protect the Clip. You don’t want the Clip to show up at SanDisk in pieces, and you probably have a small box around that you can use …
