Loto’s Sword and the Thief’s Key, from the Dragon Quest Legendary Weapon Metal Key Ring collection. There’s a pretty wide selection of these lovely metal Dragon Quest artifacts at Strapya.

Though Strapya suggests getting a strap attachment, which I didn’t realize you could get separately, and attaching one of these and your keys to your cell phone, that’s  a really terrible idea that will only lead to severe trauma for the surface of your phone.