Geno Industries 20989 25/BX GM AND FORD PUSH TYPE RETAINER, box of 25

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.