Quality, Function and Style. The GEO 2.0 has an upgraded look with a stainless steel accent ring and new color combination and now includes Dual Algorithm, Deep Stop option and a redesigned user interface with "Step Back" which allows forward and backward navigation through menus and settings. Additionally, a second Nitrox mix (both programmable to 100%) is available, as well as Firmware Auto-Update which allows the user to download and install operational improvements or even future new features through the PC Interface (with optional cable).