JUST TURN THE DIAL FOR PRECISE CONTROL :Never Worry About Losing the Remote! EASY TO INSTALL, EFFORTLESS TO OPERATE : We Bring the Gear, You Bring the Tools! Equipped with stainless steel insect screen Motor made of pure copper core, reliable and highly efficient Fan with 10 blades, running more stable and more quiet Bidirectional air exhausting with LED light Insulation made of imported EPDM sponge, water proof and sound proof, hard to age Case made of imported engineering plastics, long-lasting and anti-yellowing. Drilling size: 11.0211.02in. Air Flow Volume:8 CBM/Min. Dimensions:360 x 360 x 175 mm. Cut-out Dimensions:280 x 280 mm. Installation Thickness: 51-100 mm. To change the mode of the running fans, please first turn the switch to STOP and wait for the fan to stop completely. Then turn the switch to the expected mode.