A top cap for securing items during shipping is disclosed. The top cap consists of a body having one or more features configured to engage the top of the item being shipped. In certain embodiments, the engagements features are adjustable and may accommodate different sizes of items to be shipped. The body also comprises one or more constraint securement features configured to receive constraints such that the top cap may be secured to structural elements of a container in which the item is being shipped. Although not limited to particular applications, the top cap is particularly suited for securing computer racks for shipment.