Motorola on Thursday unveiled Moto Z and Moto Z Force, its first devices compatible with the new Moto Mods. Moto Mods are magnetic swappable backs that bring additional features to the phones, like speakers, a projector and external battery packs. The 5.5-inch Moto Z, which the company claims is the world's thinnest premium smartphone, has a thickness of 5.2 mm.