The Porsche 911 Carrera S (991) is currently the technologically most advanced and fastest performing Carrera S production model to date. After various prototype shots and renders had been released on the internet, the 991 was first unveiled at the 64th Frankfurt Motor Show in 2011. The 991 is offered with a 7-speed manual gearbox and a 7-speed PDK (Porsche Doppelkupplungsgetriebe) automatic transmission. It has a longer wheelbase than the 997. The anti-roll bar of the 991 utilises hydraulic cylinders, enabling better handling performance.