The pocket is made of crazy horse leather to hold your Stemoscope PRO. You can clasp your Stemoscope PRO to your lanyard or key chain. Crazy horse leather is full-grain leather that gets better and more beautiful with time and usage. Rather than wear out, a crazy horse leather develops a patina. The leather is made from an entire cowhide. Apart from the hair, nothing else is removed. You can easily tell the history of the cow from which it is made by the spots and marks on it. Crazy horse leather is not from horse leather as the name might imply. It is called ‘crazy horse leather' because it is used for horse saddles. The word ‘crazy' signifies its toughness as it can hold a horse no matter how strong it is.