Tube of oil(?) in my humi

[Bear]

Martin has it right. That's a "humidifier" that you will oftentimes find in a glass top Cohibo box.
They claim it's for humidification, but it doesn't even do that. So not only do you get bogus Cohibas, but they dry out as a glass top "Cohiba dress box" doesn't keep humidity and this wooden bar doesn't do anything either.