Whenever you need larger blood samples for testing glucose, hemoglobin, cholesterol, blood type studies, coagulation, blood gas and many others. Features include: (1) Intuitive two step operation and contact activation; (2) Improve patient comfort with silicone coated needles; (3) Increase safety using a double spring mechanism to ensure high puncture speed and complete retraction; (4) Self-destructive mechanism prevents possibility of reuse; (5) Gamma sterilized with a twist-and-pull tab for reliable, secure sterilization protection.