For the $1.50 you're paying for this jar you may question its quality. But I was pleasantly impressed. These jars are made out of good solid materials. I am able to tighten the lid down as tight as I can get it with my hands and have it not jump threads.
I've had other brands of jar leak at the lid when shaking but not the Tamiya jars. They seal tight and snug. The plastic lid, although clear, doesn't discolor very easily and due to the good seal is easy to clean as the threads aren't all covered in thinned paint as long as you're careful.
As the previous review mentioned the measuring marks are an added touch to help measure out thinner for airbrush applications or thinning putty.
Long story short is that i'll probably be adding a few more of these to my next order. I'd happen on them purely by accident and picked one up to test. It was money very well spent. Now I can toss all my old jars with poorly fitting lids in the trash and replace them with these Tamiya jars.