MY first three OXO storage containers work perfectly, is 5 stars for those. I just bought a fourth one, and the lid is malfunctioning. It pops way down and stays there, I have to bob it several times before it will pop up so I can open the container. I worry that one of these days it will just refuse to pop up. Anyway, it is not working right through no fault of mine. I'm not pounding it, and it is broken, so I'm not thrilled with the product. Won't be buying any more.