Complex sentence: Mods are case-like accessories that are attached to the rear of the Moto Z via a series of magnets; they can communicate via the pogo pin connectors on the rear of the device to provide additional functionality.
Split into simpler sentences: Mods are case-like accessories that are attached to the rear of the Moto Z via a series of magnets. Using the pogo pin connectors, Mods can communicate with the device to provide additional functionality.