New tablets iPad Pro (M4) and iPad Air are already available for ordering, and Apple’s website reveals some additional information about these devices that was not mentioned during the announcement.
Thus, it turned out that the new products have changed the operation of the mobile communication module. So, engineers have removed the physical SIM card slot from the iPad Pro (M4) and iPad Air 6. Now, in models with mobile support, you can use only eSIM. This is an important detail for those users who are used to changing physical SIM cards on their devices.
An eSIM is a virtual SIM card built directly into a mobile device. All the necessary identification information is stored in a miniature chip. This approach allows us to simplify the design of the device. After all, there is no need to place a physical SIM card slot, so you can optimize the placement of other internal components. This is most relevant for compact gadgets, where every millimeter is worth its weight in gold.
At the same time, this approach can be inconvenient for those users who need to transfer their mobile number (and, accordingly, their SIM card) between different devices.
Source: 9to5mac