This is the retainer clip that keeps the rocker molding (aka ground effect) attached to the rocker panel on a 2013 - 2017 (I have a 2014) Ford Fiesta ST (aka MK7 Fiesta ST, FiST). May work with other Ford models. I also tagged GM because I found the same clip at a nearby O'Reilly's auto parts store in the GM bin.
Your mileage may vary. For off-road use only. No warranty implied or expressed. Prints best on the short side with supports.