The system works without the touch of a single button. Simply place the instrument in the test stand and the system performs the test automatically; no user intervention is required. The Galaxy System is completely standalone; it does not require a computer or network interface for any mode of operation. * Order calibration gas separately. This unit comes with the calibration gas cylinder holder, regulator, memory card and charging unit. Please specify the type of monitor you have when ordering. *Order Calibration gas separately*