Feature: Rapid Venting: This shutter exhaust fan delivers 900 CFM to quickly expel stale air, floating dirt, heat, and bad smells, keeping indoor air fresh. Also works as a high-airflow exhaust fan for sheds and workshops Smooth Variable Speed: Stepless variable-speed control puts airflow at your fingertips. The included controller lets you dial the exhaust fan from a gentle breeze to a powerful blast to suit different ventilation needs Premium AC Motor: 1650 RPM and 45W provide up to 7.4 m/s airflow while running smoothly with low noise, efficient and stable for a quiet, comfortable experience. Ideal as an attic fan for year-round ventilation Tough Build: All-metal steel construction offers high rigidity, deformation-resistant, and handles damp and rain, more sturdy than plastic and ready for harsh weather Rain Guard: Shutters open when powered for ventilation and deodorizing, then close when off to block rain and small things, reliable protection for an attic exhaust fan setup Package Content 1 x Shutter Exhaust Fan 1 x User Manual 4 x Expansion Bolts M8.0x50