: Bluetooth-enabled call and message notifications, with some versions supporting independent SIM cards for 4G calling.

: Some versions listed as "None SOS" might have the physical button but lack the software enabled in that specific regional firmware.

: High-precision positioning using L1+L5 frequencies, often supporting multiple systems like GLONASS and Galileo to record outdoor routes accurately.

: Built-in 4G LTE support for real-time tracking and voice calls without needing a constant tether to a smartphone.

: 4G SOS features require an active SIM card with a data plan. If the 4G connection is "None" or inactive, the emergency button cannot dial out or send location data.

The "4G 512M" designation typically refers to the device's core communication and memory capabilities:

: Ensure the device is charged. Low battery modes sometimes disable high-drain features like GPS and cellular emergency calling to preserve basic timekeeping. Is It Right for You?

: Users may see "None" in product listings, which often refers to specific configuration packages (e.g., no extra accessories or a "None-SOS" software profile in some firmware versions). Key Features of the AML920 Series