See the attached picture. I have been using beaded chain on my Dongles. This works well since I put the attachment part inside the machine. Obviously someone could cut it but my machines are usually in racks and locations where this is not likely.
I love the USB Card, especially since I'll used USB to serial devices, USB Midi, and USB Audio. However, I have a few machines I have put as many as three Phoenix, three LFG4 Cards, or a combination with a RAID card. All which prevents me from being able to add the extra USB Cards.