Security and Convenience
I'm perennially shocked at the number of travellers I see who keep their passport in their purse, their luggage, or their back pocket. You ought always to keep it in a body pouch, uncomfortable though they may be, especially if you're American--our valuable blue passports are prime targets for theft in almost every country around the world. Unfortunately, the body pouches aren't the most convenient when heading through the airport. the train station, or crossing borders as a backpacker, and having to present ID at multiple places along the way. Fortunately, these straps are the solution. They keep your passport and other valuables secure toward the inside of your body, and in front, where it's harder for pickpockets to sneak. The convenient zipper means you can access documents quickly, without having to get undressed every time you want to access your passport pouch. I highly recommend this practical addon.