Lantus Penfill 3ml (5-pack) contains insulin glargine, a long-acting insulin used to manage blood sugar levels in people with diabetes. It provides a steady release of insulin over a 24-hour period, helping to maintain stable blood glucose levels throughout the day and night. These 3ml cartridges are designed for use with insulin pens, offering a convenient and accurate way to administer insulin. The 5-cartridge pack ensures a reliable supply for ongoing diabetes management.