The jar can be used for storage or decoration. I found this type of jar is good for use in the refrigerator. I use them for storing coffee. Good for sugar and other stuff too.The knob is depressed so it doesn't catch on anything as its is taken out or put in the refrigerator. It's made of an off white stoneware clay which I mixed. The glaze is a combination of acarmel gloss and a butter colored satin glaze. The butter satin is a liner glaze, used on the inside. The jar was fired to cone 6, which made the satin to gloss. The jar is 4-7/8" in diameter, 3-3/8" high and weighs 1lb-9 oz.