The difference between these current models and previous iPhone models is their size. The iPhone 6 has a 4.7-inch screen while the iPhone 6 plus has a 5.5-inch screen. Both of these models also come with a Retina HD display with a curved body and an NFC chip for the Apply Payment feature. [6] Both of these models had the best pre-sales in history, reaching 4 million orders in the first 24 hours. Additionally, both models surpass the previous record of 9 million sales, selling 10 million in their first weekend.