Type 1 - Connect

I think they can be used with G4 transmitter, put one on and see otherwise ask your diabetic educator,. I was a Guardian 3 user until 2 weeks ago. When I inserted a new sensor the upload did not work. I called Medtronic helpline and was told to uninstall the G3 app then reinstall it. This I was unable to do as unbelievably Medtronic had taken down the G3 app from Google Play. The person at their help line was unaware of this...unbelievable. I then had to go back to finger pricks until I was able to switch to a different system. I also had to buy a new phone as my  phone software did not work with G4, Libre2 or Dexcome 3. So for 2 weeks I used finger pricks to check my BGL  and in the mean time raised a fuss with Medtronic that they had not advised end users the app had been taken off Google Play. They ended up saying that the app would be available to end April for those using it....big deal. It was a catastrophoic communication failure by Guardian. I ended up switching to a Libre 2 when I visited my diabetic educator

I had 2 full boxes of guardian 3 sensors when I received the new Guardian 4 transmitter.  I tried the guardian 3 sensors with the Guardian 4 transmitter and they worked fine for me. I was able to use up the 2 boxes of guardian 3 sensors with the guardian 4 transmitter.  It was only after I started using the Guardian 4 sensors that I started to have the "sensor update failure".  So far I have been averaging 2 failures per box on the guardian 4 sensor/ guardian 4 transmitter combination.