What is a "belt bag"?

A belt bag, also known as a fanny pack or waist pack, is a small bag worn around the waist, with a strap that goes around the hips or waist. It is typically made of lightweight materials such as nylon or polyester and is designed to carry small personal items such as a phone, wallet, or keys. Belt bags are often used by travelers, hikers, or runners who want to keep their hands free while carrying essential items. They have become popular in recent years as a fashion accessory and are often worn across the chest or over the shoulder for a more modern look.