Open label, prospective, comparative, multi-center study. All participants will get an introduction to the invasive component of the TENSORTIP COG by means of the instructions for use in English language only (incl. an illustrated short manual) and will be asked to perform a reading without further device training. Thereafter, a healthcare professional will perform an additional reading with the reference method (YSI 2300 STAT plus). In addition, blood will be drawn for determination of hematocrit. In the study, a minimum of 10 test strip vials that cover a minimum of 3 strip lots will be used. In addition multiple devices will be employed. After completion of the study the study participants will be given a questionnaire to fill out.

Inclusion Criteria:

• patients with type 1 or type 2 diabetes or healthy
• Subjects who are able to complete informed consent form (by him/herself or by his/her guardian);
• 18 years old and above;

Exclusion Criteria:

• Does not meet inclusion criteria;
• Subjects with any other severe disease in the discretion of the investigator
• Not capable to read English user instructions at the discretion of the patient
• Pregnancy or Nursing mothers
• Any condition that may prevent participants from successful participation in the trial (in discretion of the investigator)
• Illiteracy