Humalog Mix 25IU 3ml Penfill (5-pack) is a premixed insulin containing 25% insulin lispro (rapid-acting) and 75% insulin lispro protamine (intermediate-acting). It is used to manage blood sugar levels in people with diabetes, offering both quick and sustained action. The 3ml cartridges are designed for use with insulin pens, providing an easy and accurate method of insulin administration. The 5-cartridge pack is ideal for regular diabetes management.