Apple has announced a replacement program for European iPhone adapters sold between October 2009 and September 2012 after discovering they may overheat and pose a safety risk. The affected adapter, Model A1300, was packaged in with European sales of the iPhone 3GS, iPhone 4, and iPhone 4S, and was also sold separately. Model A1300 was replaced by an almost-identical adapter, A1400, in 2012, which is not affected by the safety issues. Even conservative estimates would put the number of A1300 chargers currently in public hands in the millions, making the replacement program a major undertaking for Apple.