Insulin pens are medical devices used by people with diabetes to deliver insulin. They are designed to make insulin injections easier and more convenient compared to traditional syringes. Insulin pens come pre-filled with insulin or can be reusable with replaceable cartridges, allowing for precise dosing. These pens typically feature a dial to set the desired dose and a needle for injection. Many models are compact and portable, making them suitable for use at home or on the go. Insulin pens help improve adherence to treatment plans by simplifying the injection process for users.