https://www.cnet.com/news/why-the-moto-z3-has-a-5g-mod-instead-of-5g-inside/

Motorola's 5G Mod, in prototype form.

Last week, the phonemaker and wireless carrier teamed up in Chicago to announce the Moto Z3, a Verizon exclusive and the first phone to be upgradable to 5G when Verizon turns on its first 5G networks in early 2019.