VTG Batman or Batgirl logo pin in all black with c-catch back

Medium sized pin of the Batman logo is matte black and fairly heavy. Has a sharp c-catch or c-clasp back. Could be good for Halloween coming up! Use to secure your Batman cape! Or Batgirl cape! About 2 x 1 inches at widest points. Material is metal. what do you call a brooch back that has a stick like a needle and to attach the brooch it goes under a hook element