Machemer R, Parel J M, Hickingbotham D
Arch Ophthalmol. 1980 Jan;98(1):154. doi: 10.1001/archopht.1980.01020030156020.
A metallic tube is attached to the operating table or wrist rest, acts as a support for the assistant's hand, and provides free air flow during vitreous surgery while the patient is under local anesthesia.