Key Information: ‣ Size: 4mm ‣ Uses: BD Micro-Fine Pen Needle ensures comfortable and precise insulin administration when used with insulin pens ‣ Directions: Attach the needle to the insulin pen, inject, and dispose of the needle after each use ‣ Warnings & Precautions: For single use only. Dispose of used needles in a proper sharps container. Keep out of reach of children