This was designed to go on the end of segmented hose to spray a mix of air and liquid lubrication for use in a cnc machine.
A tube connects the nozzle to a container with the lubricant. The flow of air (tested at 3bar) draws in the fluid trough the tube and mixes it with air. The tube entrance is tapered to accept tubes from 3 to 6mm. (1/8 to 1/4 inch)
More information at: http://robosavvy.com/forum/viewtopic.php?p=35892#35892