The purpose of this study is to collect clinical data to support a 7-day wear of the Extended Wear Infusion Set (EWIS).

Participants will be asked to:

1. Wear the EWIS for up to 7 consecutive days for 12 consecutive wear periods
2. Perform blood glucose and ketone measurements if continuous glucose meter is ≥250mg/dL for one hour

This is a multi-center, single-arm, prospective study of an extended wear infusion set in adults with Type 1 diabetes using a Tandem t:slim X2 insulin pump with Control-IQ technology with continuous Glucose Monitoring (CGM). Up to 300 participants across the United States age 18-80 will be enrolled in up to 20 investigational centers. Participants will change insulin cartridge every 48 to 72 hours as recommended by their health care provider. Participants will be expected to participate in the study for approximately 12-16 weeks.

Inclusion Criteria:

• Inclusion Criteria:

  1. Age 18 to 80 years old inclusive

  2. Generally in good health, as determined by the investigator

  3. Living in the United States with no plans to move outside the United States during the study

  4. Diagnosis of T1D for at least 12 months

  5. Minimum of 6 months of insulin pump experience and at least 3 months of current experience with a Tandem pump

  6. Using Tandem t:slim X2 insulin pump with Control-IQ technology for a minimum of 1 month at the time of enrollment

  7. Minimum of 14 days of Control-IQ data immediately preceding screening that demonstrate pump use compliance, including at least 85% of time with Control-IQ technology active

  8. HbA1c <9.0% in the last 6 months.

  9. Willing to implement and adhere to pump alert/alarm settings on a study-provided pump as instructed during the study

  10. Willing to wear each investigational infusion set for up to 7 days during each of the 12 consecutive wear periods in the study

  11. Willing to perform blood ketone and blood glucose (fingerstick) measurements as directed using provided ketone and blood glucose meters and strips

  12. Access to internet for required periodic uploads of study device data

  13. BMI in the range 18-35 kg/m2, both inclusive

  14. Currently using one of the following insulins with no expectation of a need to change insulin type during the study:

      1. Humalog™* (insulin lispro)
      2. NovoLog™* (insulin aspart)

  15. Using Humalog™ insulin lispro or NovoLog™ insulin aspart for a minimum of 1 month at the time of enrollment

  16. Willing to change insulin cartridge every 48-72 hours, as recommended by patient's healthcare provider during the study

  17. Has routine access to a smart phone e.g., ability to receive text messages

  18. Has the ability to understand and comply with protocol procedures and to provide informed consent (i.e., English proficient in both verbal and written communication)

Exclusion Criteria:

1. Concurrent use of any non-insulin glucose-lowering agent, other than metformin (for example, GLP-1 agonists, Symlin, DPP-4 inhibitors, SGLT-2 inhibitors, sulfonylureas)

2. Female subject is pregnant, planning to become pregnant, or not using adequate method of contraception

3. Episodes of severe hypoglycemia in the last 6 months resulting in:

   1. Medical Assistance (i.e., paramedics, hospital evaluation or hospitalization)
   2. Loss of consciousness
   3. Seizures

4. One or more episodes of diabetic ketoacidosis (DKA) in the last 6 months requiring hospitalization

5. Currently on a ketogenic or low-carbohydrate diet of less than 60 grams of carbohydrates per day, or intending to begin one during the study period

6. Known cardiovascular disease considered to be clinically relevant by the investigator

7. Known history of any of the following conditions:

   1. Cushing's Disease
   2. Pancreatic islet cell tumor
   3. Insulinoma
   4. Lipodystrophy
   5. Extensive lipohypertrophy, as assessed by the investigator

8. Currently undergoing treatment with:

   1. Systemic oral or intravenous corticosteroids (current or within the last 8 weeks from screening),
   2. Thyroid hormones, unless use has been stable during the past 3 months

9. Significant history of any of the following, that in the opinion of the investigator would compromise safety or successful study participation:

   1. Alcoholism
   2. Drug abuse

10. Significant acute or chronic illness, that in the opinion of the investigator might interfere with safety or integrity of study results

11. Current participation in another clinical drug or device study

12. Immediate family member (spouse, biological or legal guardian, child, sibling, parent) who is a study site personnel directly affiliated with this study or who is an employee of Capillary Biomedical