Store a minimum of one finger from each hand. This means that you can operate your fingerprint scanner with your other hand if you injure one. The index, middle, and ring fingers work best. In general, minor injuries to the finger are not a problem for the fingerprint scanner. However, we recommend storing at least 2 fingers per user, for example the left and right index finger. In addition, the fingerprint scanner learns from ongoing use, so the growth of children’s fingers (from 5 years of age), for example, is not a problem. Test newly stored fingers immediately!