Based on an actual perk title from the first two Fallout games. The "Childkiller" perk was 'awarded' after the player..well, you know..
Backings: 1 Rubber Backing
Enamel: Soft Enamel
Plating: Black Nickel
Shipping Time: All orders ship same-day or next-day, and typically arrive within 2-3 days of ordering.
Standard backings are either Rubber or Metal Butterfly backings. These will securely hold your pin on, but locking backings are almost guaranteed to keep your pin in place. Think of them as 'pinsurance' for your most prized pins.