1 No heat 2 No water(Need use pure essential oil) 3 No ultrasonic 4 Refillable fragrance oil container 5 Cold-air diffusion technology/dry gas technology 6 Being silent when it works 7 With fan system to improve diffusing scent smell 8 Suitable for various area from small to big(800ml oil bottle, can be suitable for about 2000cbm) 9 Friendly and easy maintenance and operation 10 Stand-alone diffuser & HVAC system or hang on wall 11 With timer program, persistence, concentration setting. 12 Environment protecting