A method, system and graphical user interface for service level selection, for use in connection with a data network that supports multiple service levels. The tag cache includes tags of recently accessed memory blocks, each tag corresponding to one of the memory blocks and each tag including tag contents. At least some of the device cells have more than one gate trench per cell pitch. The pilot oxidizer flow is rich mixed with a pilot fuel flow, and the mixture is partially oxidized in a catalyst, with hydrogen being formed. A chassis, provided underneath the evacuation cabin, is mounted with an axle for installing wheels so that the evacuation cabin can stand stationary or be transported as a trailer by a mobile.