Full flap messenger bag is also known as courier bag. It is a sack made of leather material. Postmen have used the bag as courier bags for a long time. The bag has now become an urban trend. For short-distance travelling, this kind of bag can be commonly used for carrying essentials. Today’s era is full of online shopping. And, often full flap messenger bag is observed on the back of bike couriers. The bags are easy to carry and manage.