It is a Dexcom G6. It self calibrates when you apply the patch and input the sensor code in the app. It takes 2 hours for calibration, then stays calibrated for 10 days.
If you don’t put in the sensor code there is a manual procedure with using the glucose monitor. But I have never used it.
This is a new device. I have only had it for a month.
I’ve had my Dexcom G6 since last December. I love it. Some sensors tend to need some calibration and some don’t. I can usually tell when one is out of whack. It has helped by showing me swings between meals I didn’t know I was having because I wasn’t checking it then. You can share the data with someone so my wife gets high and low alerts.