1. From left to right side: Lighting Key (K1), Timer Key (K2), LED Display, Speed Key (K3), Power Key (K4) 2. When the power supply connected, all indicate lighting is On and then Off in 1 second. To press K4 to open the hood. 3. When the hood is On, to press K3 to open Fan Speed 1 st , to press again to open Fan Speed 2 nd, as so forth, to open Fan Speed 3 rd and 4 th by K3. The Fan Speed is changed as 1-2-3-4-0-1-2-3-4. 4.