This book has two card slots, nicely fitting a Nexus card, business cards or credit cards. It has a hidden pocket on both sides plus a pen loop.
 
As shown, the right hand hidden pocket is holding a standard field note book (included). Passports can be interchanged with the field note book, tucked in the hidden pocket as shown or tucked beneath the field note book.
 
This version is made from premium vegetable tanned leather