Choose An Hood Based On the Dimensions of the Room, Or Rather a Cubic Meter of Air. There are hoods with a built -in Dlavay Timer — Their Wiring Is Broust to the Switch. After the Light is Stewed in the Room, Such An Extract Continues to work for 3, 5 or 10 minute, Depending on the Time Exhibited on the Timer. Before Mounting the Hood, Thoroughly Clean The Shaft to AchievE Better Traction. The Holes Shoup Be Drilled Under the Fasteners of the Houod.