Abstract: The invention provides an easily transportable, general purpose box which may be carried about by hand and then anchored to rails and locked in place. Once the lid is locked on the box, no one without a key can move the box from the anchor rails. The invention is primarily intended as a portable trunk for mounting on a truck; however, it may be used anytime that a box is to be mounted on a chassis, such as a toolbox mounted on a wheeled dolly, a toolroom shelf, or the like, for example.