A biometrics system captures and processes a handprint image using a structured light illumination to create a 2D representation equivalent of a rolled inked handprint. The differential pressure indicator is configurable to provide open circuit or closed circuit logic and includes a housing, a pressure responsive element, a post, first, second and third electrical contacts and an electrical insulator from an insulative material. The presence of gas lowers the density of the agglomerates relative to the particulate material in them, so that transport of the particulates is improved. The mobile device may then request positioning assistance data based, at least in part, on the particular region. The lever plate can be put in a middle position so that two sides of the lever plate will be blocked by the middle portion of the tong body ends, making them unable to be opened.