Hi, got put on the 780G and the guardian sensor 4 which does come with it's own transmiter. Previous models use the guardian 3. I personally wouldn't want to use it if you are on a previous pump and sensor, i'd stay with it, unless you are on the heavier side as i've been left with lumps, and a rash and now can't use either my legs or my abdomen for my pump, which also leaves lumps. My previous pump i didn't have issues with. Also if sugars are unstable you won't be able to use the sensor. I've tried 4 in a week and all 4 have failed, rang Medtronic, and they advised was due to levels not being stable enough for the device.