Hi
@rupertl ,
Arguably, the most common system in use is the Freestyle Libre. With this system in its basic condition, you have to scan the sensor (usually worn on the arm) with a reader.
You can get other devices such as Miaomiao which sit on top of the libre and connect to the Libre and basically turn Flash Glucose Monitoring (FGM) into Constant Glucose Monitoring (CGM).
There are quite a few users in the forums so they'll probably pop in later with some helpful advice.
Also look at Dexcom G6.
Welcome to the forums and to our exclusive club.