WellFine 34G (0.18 mm) 4 mm pen needles are engineered for use with insulin pens in medical, wellness, orthopedic, and rehabilitation settings. The design pairs a fine-caliber cannula with a 4 mm length to fit standard insulin pen devices and support consistent injection technique.
By using a thin-wall construction, these pen needles maintain a compatible internal flow path while reducing the outer diameter. This configuration is intended to help minimize skin trauma and support careful site rotation as part of routine injection practice.