A self defense money clip. Huh. Is that a good idea? Seems like an attacker might consider your money, like, his primary reason for attacking you, and if he got it all tidily stored in a lightweight clip of durable aluminum construction with an integrated finger hole he might realize pretty quickly that he'd also scored a bonus in the form of a weapon to use in ensuring you are not able to get your money back. Also, having to take the time to remove a wad of cash and cards from the thing that's supposed to save you in an ambush doesn't seem like the most logical process.
But the 2" x 2" clip still looks cool. And holds your methods of payment commendably with its stainless tension securer. And probably most people who buy these "personal safety" tchotchkes don't end up using them for much more than staged Mortal Kombat fights in the backyard with their friend Cornelius anyway. So I guess I recommend getting one. Or not getting one. Definitely one or the other.