Supported with Avaya IP Office Release 7.0 and higher 
 The Avaya 3749 telephone supports the following features:
      
        - Intrinsically Safe Handset
- Same feature set as 3740
- Conforms to ATEX and IECEX for
 Gas: II 2G Eex ib IIC T4
 Dust: II 3D Ex ibD 22
 
- Color display
- Bluetooth support for headsets
- Position sensor (man down / no movement) for integration into security systems (requires AIWS server with OAP protocol and applicable alarming application)
 
- Limitations due to power constraints for intrinsically safe handsets:
 Display brightness is lower
 The keypad has no backlight for security reasons
 The vibrator and sound are not activated simultaneously (Ringing and vibration alternate)
 The ring signal/beeper volume is slightly lower
 
- Loudspeaker volume is slightly lower