Available on FT1 Thermal Mass Flow Meter, Gas-SelectX® feature includes added pure gases and expanded 3-Gas Mix feature. Gas selection menu allows user to choose from list of different gases — in the field — for meter to begin measuring flow of specified gas. If 11 pure gases listed in menu are not right for particular mix, 3-Gas Mix option lets user choose any 3 pure gases (not including Natural Gas) from menu and mix them in 1% increments to total 100% custom mixture.