Many phones with dual SIM slots usually feature a dedicated micro-SIM slot along with a hybrid holder for microSD cards and nanoSIM cards — put in one, lose the ability to put in the other. But if you’re willing to buy a Sony phone, you’ll be in for a pleasant surprise.
— Sony Xperia FR (@SonyXperiaFR) May 22, 2017
Dual SIM with 64GB onboard memory or single SIM with up to 256GB expandable with MicroSD card.
That said, Sony has a fairly positive history with giving out extra space for memory and SIMs — it did so for the Xperia Z5, for example.