BD Micro-Fine Plus insulin pen needles, 4mm (0.23mm / 32G) size, containing 100 sterile needles. General information about insulin pen needles: Usage: Used for subcutaneous injection of insulin in diabetic patients using compatible injection pens. Specifications: Features a length of 4mm and a thin diameter (32G) to reduce pain sensation during injection. Sterilization: Each needle is individually packaged and sterilized for single use only. For sale individually or in bulk. Individual price is 50, negotiable.