Various items are often carried on a user's belt for ready access. These items can include ammunition magazines, flashlights, mobile phones, or other electronic devices. Each of these items comes in varying sizes, although each is likely to fall within certain range of variance. Typically, to hold such items securely, a holster or carrier must be sized to the particular dimensions of the item. Specialized holsters designed to hold one specific item or size are costly to manufacture because many different models must be designed, made, and maintained in inventory.
Existing carriers that will accommodate items of varied size typically are in the form of a pouch made of fabric or other flexible material that is either stretchable or includes elastic panels. Such soft pouches give the item little protection against damage caused by impact against another hard item or surface. Other adjustable holsters either vary in only one dimension or are not self-adjusting, requiring pre-adjustment to a specific size.