Easy-to-use rotary control lets you adjust the fan speed, Optional remote control will activate down draft from an alternate location (RMDDRBK sold separately), Chimney rises over 9-1/2 inches when activated, ideal for large pots and pans, Compatible with optional Broan Make-up Air Dampers (sold separately) to fit 6" or 8" ducting and help to balance the air pressure when the range hood is in use, keeping your environment comfortable, Models RMDD3004EX, RMDD3604EX and RMDD4804EX offer you choice of exterior blowers ranging from 660 to 1620 Max Blower CFM or in-line blowers from 320 to 1540 Max Blower CFM (blower required and sold separately), Dishwasher-safe filters are easy to remove and feature a stylish brushed stainless steel appearance for a professional look, Retractable downdraft hood rises from behind the cooktop and retracts when not in use, offering a seamless design for your kitchen, Unique ducting capability allows the external blower connection to be ducted to the left, right or downward (from left to right), Heat Sentry(R) adjusts speed of blower to High automatically in case of excess heat, to prolong product life