A butterfly needle is a device used to access a vein for drawing blood or giving medications.
Some medical professionals call a butterfly needle a “winged infusion set” or a “scalp vein set.” The set gets its name because there are plastic “wings” on either side of a hollow needle used to access the vein.
While some elements of the butterfly needle can vary, most have a needle in a winged sheath or plastic covering that’s pulled back to reveal the needle. The needle is attached to tubing that may have a luer lock. This is a type of connection that you can twist a syringe onto.