The nEXT 85 pumps consist of the turbo molecular pump with a permanently attached controller containing drive electronics and comes configured with two different variants, the "D" and "H". The "D" variant incorporates both turbo molecular and drag stages for improved tolerance to higher backing line pressures.The High Compression -"H" variant employs the same technology as the 'D' variant, but is tuned to deliver higher compression. The controller controls the electrical supply to the pump with the exception of standby speed control. It has no manual controls and can only be operated through the logic interface. To operate the nEXT-85 pump you must connect it to your own control equipment and power supply or alternatively use the Edwards TIC Turbo Instrument Controller or TIC Turbo Controller. nEXT 85 pumps are supplied with an inlet-screen fitted into the centering O-ring for ISO version pumps and into envelope for CF version pumps. nEXT85 pumps with an NW 25 interstage-port are supplied with an inlet-strainer that fits into the interstage-port. The inlet-screen and inlet-strainer protect the pump against damage that would be caused by debris entering the pump. The nEXT 85 pumps have a vent-port for venting the pump and vacuum system to atmospheric pressure. The pump is supplied with a manual vent-valve fitted; this can be replaced with a TAV5 or TAV6 solenoid-operated vent-valve.