This keeps it clean which prevents the unit from malfunctioning, and the lock on the case deters people from stealing the device. Expensive laboratory equipment used for field research, rare firearms, musical instruments and GPS devices are also often stored in heavy duty equipment cases.
The exterior of an equipment case is tough and rigid to protect whatever is inside from drops or sudden impacts. Sometimes manufacturers use a plastic injection molding process to create a heavy duty plastic case. Often aluminum is used as the primary material because it is light but strong.
Metal clasps are fitted to the lid of the case so that it can be tightly shut after goods are placed inside of it. In some units an integrated lock is featured on one of the clasps to add security, or a padlock can be added to a latch on the front of the case. If the equipment case is large and is designed to carry something like a guitar amp, wheels are built into the bottom so that it can be rolled across a floor.
Handles on the sides or top of the case make it easier to pull or lift the whole unit. Because equipment cases generally have a rectangular shape, they can be stacked in tight spaces like a moving van to create more packing efficiency.
Inside the case manufacturers add patterned foam padding to cushion objects placed inside so that they do not get scratched or move around when the case is moved. These cushions can be cut into a customized shape that matches the dimensions of the object being placed inside to make sure that there is absolutely no room for movement. Most large audio video equipment cases have a series of drawers and shelves built within them to allow for a complete audio setup at a concert.