Wahoo KICKR Headwind Bluetooth FanThe KICKR HEADWIND is sensor controlled so as your speed or heart rate increases, so will the fan speed, and there are also 4 manual speed settings should you want to set your own ideal airflow. With speeds of over 30 mph (48 kph), the KICKR HEADWIND will keep you cool during the toughest training sessions. Manual Mode: Select from four speed settings to set you ideal airflow Speed Mode: Pair to KICKR or speed sensor to match fan speed to bike speed