I agree. Every aircraft repair shop I've worked in or near had a couple of these. The "disk" at the top was actually more of a funnel, and there was a ring like rack that would hold five or six cans all tilted inward. Two drain cans, one for recip oil and one for turbine. You could concoct a great synthetic blend motor oil for your car from the drippings if you knew what you were doing.Look like oil drain cans to me.