https://www.youtube.com/watch?v=Hc-YEhLHexcThe pre-purchase provides both a 20% discount off the retail price and access to the Open Beta coming later this year.
Like previous DCS World titles, DCS: Bf 109 K-4 Kurfürst features a painstakingly reproduced model of the aircraft, including the external model, fully interactive cockpit, mechanical systems, and a Professional Flight Model (PFM). Along the lines of our DCS: P-51D Mustang and DCS: Fw 190 D-9 Dora titles, DCS: Bf 109K-4 Kurfürst places you behind the controls of a powerful, propeller-driven, piston engine combat aircraft. Designed long before “fly-by-wire” technology was available to assist the pilot in flight control or smart bombs and beyond visual range missiles were developed to engage targets with precision from afar, the Kurfürst is a personal and exhilarating challenge to master. Powerful and deadly, the last production model of the only single-engined German fighter to see service throughout World War II, the Kurfürst provides an exhilarating combat experience to its drivers, and a worthy challenge to all fans of DCS: P-51D Mustang.
http://www.digitalcombatsimulator.com/en/shop/modules/kurfurst/