Motorola Moto X Force Troubleshooting Manual page 4

Antenna Locations
This product has an external metal antenna band.
All antennas are made using the metal band.
There is an extra stamped metal piece on the rear
housing for extra diversity bandwidth and isolation
to GPS.
Moto X Force/DROID Turbo 2
MOTOROLA CONFIDENTIAL
BASEBAND TROUBLESHOOTING GUIDES