90mm Petri Dish Tri-Vent

I use glass Petri dishes for my work, so that I can reduce my plastic waste in the lab. Unfortunately, my glass dishes are not vented. This is a problem when I need air exchange, like crystal growing or fungi culturing. To upgrade my dishes without significant plastic use, I printed these rings. 

This ring has three raised lips with the same clearance as a standard vented Petri dish. The ring will fit snugly into the lid of the dish so that it doesn't fall into my solutions, and I can reuse them again and again.