Lone worker alarm SRT405i

SRT405i is a high quality lone worker alarm in a small and handy size and supporting indoor positioning

  • Voice over LTE (VoLTE) with 2G backup
  • Indoor positioning
  • Display
  • Up to 48 hours battery lifetime
  • Speaker and microphone
  • Motion detection
  • 99 channel GPS/GLONASS/Galileo receiver
  • Intelligent battery saving mode
  • Multiple alarm types
  • Dust and water protection (IP67)
  • Dimensions: 60x46x20 mm
  • Weight: 54 grams

SRT405i is the result of years of experience developing lone worker alarms and comes fully loaded with handy functions.

SRT405i can handle a range of different alarm types. The big red button is normally used for emergency situations. The two function buttons can be used for less critical situations or for communicating with secondary alarm receivers. Automatic alarm types such as ManDown (based on the device rotation) and Timer-alarm (timer based alarm) are also supported.

Indoor positioning

SRT405i supports indoor positioning based on communication with RF tags (SRT334i/SRT334i2). An area with no GNSS coverage can be equipped with RF tags and each tag is programmed with specific position data. When SRT405i enters an area covered by a specific tag it receives the preprogrammed information. The range of the radio signal from each RF tag can be adjusted to achieve the desired coverage.

SRT405i has the ability to assess the optimal positioning method in any given situation. When available it will use GNSS and when not available it will instead attempt using RF positioning.

Further configuration of positioning methods is also possible. For example, you can have the SRT405i use RF positioning during office hours. Or set it to switch to RF positioning upon arriving at a certain geographical location. Provided the SRT405i is outside and receives a GNSS position it can decide when it enters the designated area and can then switch to RF positioning.


SRT405i is equipped with a display for easy interaction with the device. The device menu allows you to change settings and view status messages. And during an emergency situation, all device events are clearly displayed.


With SRT405i you can choose the report format that suits your needs. It supports many standard formats and the possibility to create completely custom formats. Alarm reports can be sent to multiple receivers making the SRT405i fit for use cases requiring redundant means of communication.

SRT405 front view
SRT405 top view
SRT405 side view
SRT405 bottom view