What is the glucose range that Lingo shows? Lingo displays a range of glucose values from 55 to 200 mg/dL (3.1-11.1 mmol/l). Related articles Are biosensors waterproof or water resistant? Can I use Lingo if I'm on Insulin? Can I use Lingo if I have problematic hypoglycemia? How can I contact customer support? Do you offer a money back guarantee?