Geno Industries 17267 15/BX ACURA PUSH-TYPE RETAINER 20MM HEAD DIAMETER 15MM LENGTH, box of 15

They work by pushing in the center pin which spreads the prongs. They are used for retaining bumper guards, various fascia, splash shields, shrouds, etc. While they are designed to be reusable, they are made of nylon and are usually destroyed in a collision. They are sometimes referred to as rivet retainers or drive-type retainers.