This year, Apple is expected to release 4 OLED handsets in three display sizes. The sizes of displays are like 5.4, 6.7, and two 6.1-inch mobiles. According to the trusted sources 6.1, and 6.7-inch models are going to be higher-end handsets.
Apple will be using a 5-nanometer A14 chip in these lineup handsets, which are to be released in 2020. These handsets are going to be smaller and battery efficient devices by improving thermal management. This improvement from Apple is going to be unique from there past handsets.
Sources claim that pro handsets are going to accommodate 6GB of RAM, and the other models are to accommodate 4GB of RAM as usual. We can expect 6GB RAM from a 6.7-inch and one 6.1-inch handset. And 4GB RAM with one 6.1-inch model, and a 5.4-inch model.