https://www.theregister.co.uk/2018/05/29/moto_to_possibly_add_5g_to_4g_with_magnets/

Lenovo's Motorola may soon offer 5G through its Mod phone expansion system, which allows peripherals to clip to the back of Mod-compatible phones using a magnet, according to leaked imagery.

The images, published at XDA developers, include a bulky 5G Mod. The Moto Mod bus supports USB 3.1 speeds: sufficient for the gigabit data transfers of 5G.