F-duct

An F-duct was an aerodynamic device used in Formula 1 racing in 2010 that allowed drivers to reduce drag on straightaways for higher top speeds.

The system consisted of channels running through the car's bodywork that could be activated by the driver covering a small vent, typically with their hand or leg. When activated, the F-duct directed airflow to "stall" the rear wing, significantly reducing drag and increasing straight-line speed by up to 10 km/h.

First introduced by McLaren (nicknamed "F-duct" due to the F-shaped Vodafone logo near the inlet), the system was quickly copied by other teams before being banned in 2011 due to safety concerns about drivers removing hands from the steering wheel. It was later replaced by the standardized DRS (Drag Reduction System).