ASUS Zenfone 2 Out Of Stock In Pre-Order On Flipkart – 25,000 Units Being Booked In 24 Hours ASUS today announced that the recent launched revolutionary ASUS Zenfone 2 which was announced available for pre-order on April 23, 2015 through ASUS Exclusive Store and on Flipkart 25,000 units being booked April 29, 2015 News