Humulin N 3ml Penfill (5-pack) is an intermediate-acting insulin used to manage blood sugar levels in people with diabetes. It contains insulin isophane, which provides a slower and longer-lasting effect, helping to control blood sugar over a period of up to 18 hours. The 3ml cartridges are designed for use with insulin pens, offering a convenient and precise method of insulin administration. The 5-cartridge pack ensures a steady supply for ongoing diabetes management.