Hall Current Thruster (Primex Aerospace Company)
The Hall Curent Thruster (HCT) is a plasma thruster operating on gaseous xenon propellant. Its performance of 1500-1800 seconds of specific impulse and 50% efficiency make it nearly idea for many earth orbital propulsion requirements including North-South stationkeeping and orbit insertion maneuvers.
Electrothermal Hydrazine Thruster : Iridium Thruster 