Thank you very much for looking. m(_ _)m This is a petri dish with a lid. It's made of thick, sturdy glass. I have three more, so please contact me if you need a lot. I received this as a gift, but I don't have any use for it, so I'm hoping someone else can make use of it... (*^^*) The diameter is about 10cm. I think it's in good condition, but it's a used item that has been handled by someone else, so please understand this before purchasing.