It has strong ventilation because it upgrade fully closed pure copper motor offers fast fume suction, ventilation, keeping the indoor air clean and comfortable. It has seven thickened blades deliver more powerful and uniform air volume, not easy to deform. It runs stably and vibration-free, ensuring large air volume while reducing noise. It is constructed of iron material. There are several sizes for your choice: 6inch, 4Inch, 7inch. Easy to install, suitable for kitchen, toilet, office, meeting room, restaurant, supermarket, cinema, Internet cafe, workshop, waiting hall, etc. Item Name: Exhaust Fan Material: Iron Features: Bass Noise Cancellation, Strong Wind, Super Suction Voltage: 22V Frequency: 50 Hz Size Details: 4Inch Black, Diameter: 10cm/3.94 (Approx.) 4Inch Black, Length: 7.3cm/2.87 (Approx.) 6inch Black, Diameter: 15cm/5.91 (Approx.) 6inch Black, Length: 15cm/5.91 (Approx.) 7inch Black, Diameter: 18cm/7.09 (Approx.) 7inch Black, Length: 14cm/5.51 (Approx.) 4Inch White, Diameter: 10cm/3.94 (Approx.) 4Inch White, Length: 7.3cm/2.87 (Approx.) 6inch White, Diameter: 15cm/5.91 (Approx.) 6inch White, Length: 15cm/5.91 (Approx.) 7inch White, Diameter: 18cm/7.09 (Approx.) 7inch White, Length: 14cm/5.51 (Approx.) Notes: Due to the light and screen setting difference, the items color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Exhaust Fan