These small plates (~2.5cm x 1.7cm) of shungite (99% carbon) have adhesive on the back to allow them to be adhered to the back of a cellphone or cellphone cover.
These are provided by popular request because of the belief that shungite adhered to the cell phone may help protect the user from radiation and electromagnetic waves. Take care of your shungite plate, as shungite is not very durable.
Because these are real stone, there are natural variations between each one. When ordering online, your plate will be intuitively chosen for you and may not be the one from the photo.