The FreeStyle Libre 2 Sensor is 5mm in height and 35mm in diameter.

The FreeStyle Libre 3 Sensor is even smaller at just 2.9mm in height and 21mm in diameter.

The portion of both Sensors that gets inserted under the skin is less than 0.4 mm wide and it's inserted only about 5mm under the skin. In a study conducted by Abbott Diabetes Care, users agreed that inserting the Sensor was no more painful than a typical finger prick glucose test*.

*Data on file. In a study conducted by Abbott Diabetes Care, 93.4% of patients surveyed (n=30) did not feel discomfort under the skin while wearing the Sensor.