CZ Infrared Blue Edition Therapeutic Infrared Quartz Portable Heater/Air Purifier - 6800 BTU, 1500 Watts, Model# CZI-1500-PA Longer, heftier, more powerful heating elements now lasting 30,000 hours 115 Volts rather than industry standard 60 Volts (more volts = more efficiency) Accurate digital thermostatic controls Heating element filament now twice the density Improved patent-pending ceramic terminals for greater durability and longevity