They are called StoryPhones and are a proposal from Onanoff that plays audiobooks through a system of collectible magnets.

StoryPhones work through a proprietary technology that consists of reading small magnetic disks that can be attached to the outer sides of the phones.

From afar, the StoryPhones look like any other pair of headphones for kids, but these support wired and/or Bluetooth connections and their battery life is 20 hours of operation.

To access the stories contained on these magnetic disks, the headphones must be connected via Bluetooth to an adult's smartphone so that they can connect to the Internet. The child simply places the disc magnetically on the side of the headphones, and the headphones download the corresponding story and store it in their internal memory (64MB is enough for about 90 minutes of content).

Once a story is stored, the child can access it whenever they want, instantly, without the StoryPhones needing to be connected to the Internet.