Cal. 11C5 is a hand winding ultra-thin movement with power reserve indicator from Manufacture Blancpain (formerly Frédéric Piguet). It is related to Cal. 11A4B and many other ultra-thin Blancpain movements. It features double-barrel winding for 100 hours power reserve, as indicated by a hand at 9:00 on the dial. It also features small seconds and a date window at 3:00.
Like many Manufacture Blancpain movements, Cal. 11C5 has a silicon balance spring.
Cal. 11C5 was used in the Blancpain Ultraplate, Ref. 6606, from 2010.