Apple has started production on new iPhone models that include Force Touch, Bloomberg reports. Sources with knowledge of the matter said the new iPhones have the same 4.7” and 5.5” measurements as the current iPhone 6 and iPhone 6 Plus models. Higher-volume manufacturing is scheduled to ramp up as soon as next month, with assembly expected to go smoothly, because the phones also have the same exterior design as the 6 and 6 Plus. The only potential problem is the supply and yield of the new Force Touch-capable displays, which could cause production snags or influence the timing of the new iPhone’s release, one source said. Apple didn’t comment on the story, but it was reported months ago that Apple would be adding Force Touch to new iPhone models, and iOS 9 will support the new technology.