Love when we have to go out of our "Ceramic Comfort Zone". And we did with our Barista Collection. 2/3 the thickness of our other collection. But hè that is all for you Barista"s, we've got some good advise... The cups are made of our "Red Earth" dark red stoneware clay and the other two are made of our new "Whole Grain" stoneware clay style And the walls are 5mm thick, but not the mouth rim ofcourse for that delightful sip. Sizes cups: Holds: 150ml. {2.7 Fl. Oz.} Hight: approx. 7,5cm. {2 1/3"} Diameter: approx. 7,5cm. {2 1/3"}