The Port Designs S15 Clamshell 15.6 laptop case is a sturdy yet lightweight bag, designed to transport your laptop. Its classic, popular style was developed by designers in our creative studio in Paris. This bag is called a Clamshell bag because the zipper allows it to open up completely, going around the structural frame of the bag. This system allows you to secure your computer in the bag more easily using a hook and loop strap that will encase your laptop and prevent it from falling out of the bag if it is opened suddenly.