[Extreme Heating Speed & Wide Heating Range] The 1500W infrared heater has a fast heating function, it only takes 2s to preheat, providing you with fast and effective warmth. The electric space heater also has a dual heating system that combines 6 infrared quartz tubes and PTC technology to provide 60% more heat than traditional heating systems. This means that indoor space heater for large room has wide coverage and can provide even heat throughout a room without causing the air to dry out. [3 Heating Modes & Thermostat Hold] Space heaters for indoor use have 3 optional modes including 750W mode for 64-107 sq.ft, 1500W mode for 86-161 sq.ft, and ECO model that automatically manages power to maintain constant temperature. The desk heater has an adjustable thermostat with an range of 59°F ~ 86°F in 1°F increments, ensuring you can set the desired temperature. ECO mode is particularly useful for those who want to save on energy costs while still maintaining a comfortable temperature.