The invention relates to a device for moving people or objects for the purposes of play, sport, pedagogy or therapy. As one example, a system for preventing blow-by of LN2 is disclosed, which includes a temperature sensor located near an exhaust line of a heat exchanger, a shutoff valve located in an inlet line, and a controller coupled to the temperature sensor and the shutoff valve. A second set of passages may provide a nitrogen-containing precursor gas. A capacitor conductor pattern is provided on one layer lower than the insulator layers on which the inductor conductor patterns are provided. The hearing aid further includes a first proximity sensor associated with the casing and configured to generate a first signal that is proportional to a proximity of the casing to the ear and includes a processor coupled to the first proximity sensor and configured to select an operating mode from a plurality of operating modes in response to the first signal. The toilet seat can easily be removed by merely removing the third nut and lifting the seat off the flange.