There are several third party Bluetooth transmitters that fit the Libre or you can use an old Sony smartwatch. I used the latter for a few months but it was muc

There are several third party Bluetooth transmitters that fit the Libre or you can use an old Sony smartwatch. I used the latter for a few months but it was much better when I switched to the Dexcom G5. The G5 is just a small BT transmitter and the G6 is even smaller. The insertion is a bit nicer on the Libre but not a big deal. If you use xDrip and stretch the life of the sensors and transmitters then the Dexcom isn't much more expensive than the Libre (at least for me, in the UK). Scott is using the G6 now I think, and most T1s I read online recommend Dexcom.