Common name for a kind of blood collection
set used in most phlebotomy
clinics. It consists of a small-gauge hypodermic needle
embedded in a piece of plastic
with two "wing
s" branching out that allow the technician to hold the device. The needle feeds into a ~10cm flexible tube
that is then poked into the vacuum vial for collection.
Butterflies are usually used for blood draws from the lower arm and wrist. I prefer to call them "mosquito"s, as the name fits much better, but humorless phlebotomists might not understand what you are talking about when you request for them to use one, as I found out to my chagrin on my last doctor's visit.