Target species:

  • medium gulls including Audouin’s Gull
  • small egrets & herons
  • medium raptors
  • Crowns
  • Avocet
  • Curlews
  • Oystercatchers
  • Royal  Tern
  • Wood Pigeon, etc……


Version with large 210mAh battery. Weight 15g. Suitable for larger species weighing from 500g.

Neck collar version for small swan species.


FLEX II 4G is a solar-powered GPS-4G-ACC tracker suitable for backpack deployment for birds weighing 300 grams and more.

Additionally, the device offers Bluetooth transmission with connection range of around 100m in open space.

Appearance & Measurement
Dimensions:50.3 mm x 24.4 mm x 31.1 mm
50.3 mm x 24.4 mm x 20.1 mm - Max version with 210 mAh battery
15.0 ±0.2g - Max version with 210mAh battery
Housing:ABP & PC injection molding. Strong and water proof, with multiple harness threading holes. Light brown in standard.
Data Types
GPS:Longitude, latitude, altitude, geoid height, course, satellite quantity
ENV:Voltage, light intensity, temperature
BHV:ODBA (overall dynamic body acceleration)
ACC:x/y/z acceleration data (upon request)
BSS:Longitude, latitude, altitude (alternative locating method for extreme situation)
Power Supply
Solar type:GaAs solar unit (30% efficiency) with good performance under weak light
Battery type:Lithium polymer rechargeable battery with under-and-over-charge protection
Battery capacity:30mAh 10.0g version or 210mAh 15g Max version
Fully charged battery is sufficient for logging over 300 in standard and 2000 in Max GPS positions without recharge under optimal GPS satellite view.
GPS Module
GPS precision:CEP (50%) 5m
Maximum update rate:10 Hz
Transmission Module
Bands:LTE-FDD B1,
Maximum uplink/downlink data rate: 5.76M bps/7.2 Mbps
Bluetooth Low Energy. Maximum uplink/downlink speed: 1 Mbps/ 1 Mbps
Global Roaming:Support
SMS function:Support (upon request)
Data Collection & Transmission Setting:
Regular-Interval Mode:
- GPS interval: 5 min ~1 day
- ENV interval: 5 min ~1 day
- ODBA interval: 10 min/30 min
- ACC interval: 25 Hz, 3 seconds in every 10 min (by default)
- Transmission interval: 5 min ~1 day
Above ranges are selectable on website data platform or App. Contact us if other settings are required.
On-Time Mode:
- Transmission: Up to three times at fixed hours per day (such as 13:00/14:00/18:00)
- GPS / ENV / BHV: Regular-interval model or on-time model follow each transmission
Sleep Mode
This mode is to deactivate certain type of data collection for:
- a regular period each day (a maximum of 16 hours)
Intelligent Frequency Optimization & Flight Detection (BOOST)
The BOOST function intelligently increases data collection & transmission frequency when the charging condition is good or the bird is flying. The default setting is as below:
Frequency Optimization:Every 10 min/1 min
Flight Detection:Every 20 sec
With BOOST, the device portrays detailed movement tracks without manual intervention and avoids the possibility of battery drain due to radical settings in bad weather.
Data Storage
Logged data will be stored in memory if network is unavailable.
Flash memory:16 MB
Regular data storage:460 days at default setting (1h GPS+1h ENV+10 min BHV)
BOOST data storage:280,000 pieces
ACC data storage:28,700 pieces
Operational Environment
Working temperature:-20°C~60°C
Waterproof:IP 68
Firmware Upgrade
Over the air (OTA)

© 2008-2024 INTERREX-RINGS Sp. z o.o.  - OEM Client & Authorized Distributor of Druid Technology Co., LTD.

All rights reserved. Despite great attention to correctness of information on this website, content on this website does not constitute an offer within the meaning of Article 66 of the Civil Code par.1. This site uses cookies for enhancing your experience, calculating statistics and keeping track of user visits. You can change cookies policy or disable it in your internet browser settings.


We're not around right now. But you can send us an email and we'll get back to you, asap.


Log in with your credentials

Forgot your details?