Teltonika FMM125 — Versatile LTE Cat M1 Professional GPS Tracker with Dual SIM and RS232/RS485

The Teltonika FMM125 is the LTE Cat M1 and NB-IoT version of the FMC125 — Teltonika's versatile professional tracker, now on global IoT network infrastructure for international fleet deployments. Sharing the same comprehensive RS232/RS485, dual SIM and 1-Wire feature set as the FMC125, the FMM125 delivers reliable global coverage across EMEA, APAC and LATAM with automatic 2G fallback — making it the correct hardware choice for international fleet operators who need professional serial interface connectivity on IoT network infrastructure.

Described by Teltonika as versatile and specifically suitable for fleet management, car rental, taxi companies, public transport and logistics, the FMM125 covers a wider range of professional fleet applications than almost any other single LTE Cat M1 tracker. Its RS232/RS485 interfaces support fuel sensor integration, Garmin navigation, RFID readers and barcode scanners, while dual SIM significantly reduces roaming costs for international operations and 1-Wire enables cold chain temperature monitoring alongside iButton driver identification.

As an official Teltonika distributor in the UK, Tracking Hardware UK ships the FMM125 directly from our London warehouse — with trade pricing available for telematics service providers, fleet operators and resellers.

Key Features

• LTE Cat M1 and NB-IoT with 2G fallback — global IoT network connectivity across EMEA, APAC and LATAM with NB-IoT support and automatic 2G fallback ensuring continuous coverage for international fleet deployments

• Dual SIM — automatic failover between two SIM cards, significantly reducing international roaming costs and providing a backup communication channel for global operations

• RS232 and RS485 interfaces — connect digital fuel level sensors, Garmin navigation devices, RFID readers, barcode scanners and other third-party serial devices for extended fleet monitoring

• 1-Wire interface — connects temperature sensors for refrigerated transport and cold chain compliance monitoring and iButton for driver identification — compatible with the Tracking Hardware UK 1-Wire driver identification keypad

• Bluetooth 4.0 + LE — connects to BLE sensors and EYE accessories for extended environmental and asset monitoring, and supports ADAS camera integration

• Remote immobiliser — digital output allows remote vehicle disabling via your fleet management platform

• Crash and tow detection — built-in accelerometer triggers alerts on impact or unauthorised movement

• Jamming detection — alerts when GPS signal interference is detected — supported with the Quectel BG95-M3 module

• Green driving monitoring — tracks harsh braking, acceleration and cornering for driver behaviour scoring

• Excessive idling detection — monitors prolonged engine idling for fuel cost reduction

• CAN adapter support — compatible with Teltonika LV-CAN200 and ALL-CAN300 adapters for deep vehicle data reading

• 170mAh Li-ion backup battery — maintains device operation if vehicle power is interrupted

• 128MB internal memory — stores up to 422,400 records when out of coverage

• Multiple sleep modes — GPS sleep, online deep sleep, deep sleep and ultra deep sleep for optimised power management

• Over-the-air updates — firmware updatable remotely via FOTA Web

Driver Identification with Tracking Hardware UK 1-Wire Keypad

The FMM125 supports 1-Wire connectivity and is fully compatible with the Tracking Hardware UK 1-Wire driver identification keypad. Drivers enter their unique PIN at the start of each trip and the driver ID is logged alongside all GPS and telematics data — giving fleet managers complete driver accountability across international professional fleet deployments. Contact us to discuss keypad and FMM125 bundle pricing.

FMM125 vs FMC125 — Which Should You Choose?

The FMM125 and FMC125 are identical in professional features — same dual SIM, RS232/RS485, 1-Wire and Bluetooth. The FMC125 uses LTE Cat 1 for faster data speeds on UK and European 4G networks — the recommended choice for most UK and European professional fleet deployments. The FMM125 uses LTE Cat M1 and NB-IoT for broader global IoT coverage — the recommended choice for international deployments across EMEA, APAC and LATAM where Cat M1 infrastructure is preferred. Contact us for guidance on which best suits your deployment.

Technical Specifications

Cellular: LTE Cat M1 and NB-IoT with 2G GSM fallback

GNSS: GPS, GLONASS, Galileo, BeiDou, SBAS, QZSS, DGPS, AGPS — 33 channels — -165 dBm — less than 2.5m CEP

Bluetooth: 4.0 + LE

SIM: Dual SIM

Serial interfaces: RS232 and RS485

1-Wire: Temperature and iButton

Backup battery: 170mAh Li-ion

Power input: 10V to 30V DC

Memory: 128MB — up to 422,400 records

Operating temperature: -40°C to +85°C

Typical Use Cases

Ideal for international professional fleet management requiring RS232/RS485 sensor connectivity on global IoT networks, international logistics with cross-border roaming using dual SIM, refrigerated transport with 1-Wire temperature monitoring, fuel management using digital LLS fuel level sensors, car sharing and car rental requiring remote control and RFID, taxi and public transport operators, driver identification programmes, Teltonika ADAS camera integration and any professional fleet application requiring future-proof LTE Cat M1 connectivity with advanced serial interface support across global markets.

Frequently Asked Questions

What is the difference between the FMM125 and the FMC125?

The FMM125 and FMC125 are identical in professional features — same dual SIM, RS232/RS485, 1-Wire and Bluetooth. The FMC125 uses LTE Cat 1 for faster data on UK and European 4G networks. The FMM125 uses LTE Cat M1 and NB-IoT for broader global IoT coverage. For UK deployments the FMC125 is recommended. For international IoT network deployments the FMM125 is the correct choice.

What devices can I connect via RS232 and RS485?

Digital fuel level sensors, Garmin navigation devices, RFID readers, barcode scanners and other third-party serial devices. This makes the FMM125 ideal for international fleets needing data beyond basic GPS location.

Is the FMM125 compatible with the Tracking Hardware UK 1-Wire driver identification keypad?

Yes — the FMM125 supports 1-Wire and is fully compatible with the Tracking Hardware UK 1-Wire driver identification keypad. Contact us for keypad and FMM125 bundle pricing.

Does the FMM125 support the Teltonika ADAS camera?

Yes — the FMM125 is compatible with the Teltonika ADAS camera for advanced driver assistance and road safety monitoring alongside fleet tracking. Contact us for ADAS camera and FMM125 bundle pricing.

Can I buy the FMM125 in bulk from Tracking Hardware UK?

Yes — we supply telematics service providers, fleet operators and resellers across the UK and internationally. Volume pricing and trade accounts are available. Contact us for a bulk quote.