It’s one of the standard plates. You can choose this plate instead of the one you posted without any additional fee. You have the option to pay $45 to personalize it but you don’t have to.
https://www.in.gov/bmv/registration-plates/license-plates-overview/indianas-standard-license-plates/
They’re the only weapon you can use underwater and they’re also good for knocking flying creatures out of the air.