These Agilent Varian MBA2-200T Hot Filament Gauges connect to the Newest-Style Agilent Varian XGS-600 hot cathode gauge controller cards. These Hot-cathode Bayard-Alpert Ion Gauges are the smallest Ion gauges. They are much more rugged than glass tubes and have an all metal case. They generate less heat and provide greater burnout resistance. They can measure pressure down to 3x10-10 Torr. They come in dual tungsten or burn out resistant dual yittria coated iridium filaments providing long gauge life. These have a KF25, NW25 vacuum flange fitting. Agilent XGS-600 vacuum gauge controller connection cable is required for use and sold on this website (see middle picture above, PN P106293 , Agilent Varian PN X3203-60006, 10ft.) This is the gauge only, controller connection cable not included. PDF instruction manual for use can be downloaded below at AVAILABLE DOWNLOADS: