The Federal Communications Commission has certified the 5G Moto Mod, suggesting that the attachment offering 5G capability could be on the market soon.

The Moto Z3 a phone features magnetic backings that attach to Moto Mods, or modules. The snap-on mods, which were granted FCC approval on Friday, would make the Verizon exclusive the first phone to be upgradable to 5G.

When the 5G modular attachment is snapped on, Motorola says that its Z3 phone will deliver data 10 times faster than other 4G LTE devices at speeds up to 5Gbps.

According to the 5G Moto certification document published online by FCC, the device will feature proximity sensors that shut off any of its four millimeter wave 5G antennas if your fingers get too close:

As mentioned in the device description, capacitive and proximity sensors are used to disable transmission from a given mm-wave antenna array module when a user may be located in close proximity to the module and in a direction in which the module may transmit. The control mechanism is a simple one in which, if proximity detectors indicate the potential presence of the user within a roughly conical region in front of the module where power density may approach the MPE limit, that module is disabled from use by the modem. This terminates and prevents transmission from the module in question until the condition is cleared.

What you need to know is that millimeter wave radiation is considered non-ionizing, meaning that it doesn’t have enough energy to tear apart living tissue. The FDA says there are “no known adverse health effects” from that kind of dose. In additio, the FCC has millimeter wave exposure limits already, and that’s what Motorola’s system is complying with.

The 5G Moto Mod device contains 4G and 5G redio receivers, capable of functioning in EN-DC mode. It functions only when it is snapped onto a 5G Mod-compatible smartphone device, such as the Moto Z3 Pro, according to the FCC filling.

The Mod includes its own Snapdragon 855 processor, X50 5G modem, 10 antennas, and its own 2,000mAh battery. Acording to FCC filing, the device is 7mm thick at its thickest point, meaning it’ll more than double the thickness of your 6.75mm Moto Z3 phone.

The Mod does not contain a WiFi/BT tranceiver function. Transmissions are coordinated between the host phone and the 5H Mod, but there are cses where both the cellular modem in the phone and the cellular modems in the 5G Mod are transmitting simultaneously, and/or WiFi/BT in the phone is transmitting simultaneously with the cellular radios in the phone and/or Mod.