Infusion Needles Scalp Vein Set Use with Glutathione Injection Scalp Vein Set, Disposable Scalp Vein Set Made in China.com Glutathione Synthetase Deficiency StoryMD Dr. Choukroun Blood Collection Needles 21g 35 Box Butterfly Needle for Blood Draw: How It Works and Why It's Used Blood Specimen Collection in Simple Steps , 1. Gather all necessary supplies., 2. Prepare your setup and attach the vacutainer to the butterfly needle., 3. Secure the tourniquet., 4. Palpate the Butterfly Needle: How They Work for Blood Draws