Choosing the right needle is about matching the gauge and length to the specific task, whether it's a quick vaccination or drawing blood. Here is a simplified breakdown of the most common needles used like, swipe, and save for when it's your turn to do an injection on a patient Intramuscular (IM) Angle: 90 Needle Size: 2225G, 11.5 inch Med Examples: Vaccines (e.g. Tdap, Amazon.com: Ulove Prs 12 Pack 1ml Industrial Syringes with 25Ga 1 Inch Needle, Plastic Disposable Syringe and needle for Scientific Labs, Liquids Refilling and Measuring : Industrial & Scientific Know Your Needles A Quick Nursing Guide! , Today, lets understand the different types of needles and their clinical purposes , Green Needle (21G) For IM injections like vaccines or