Fortessa Fortaluxe Superwhite Vitrified China Dinnerware, Cassia 12-Ounce Large Stackable Mug, Set of 6 Set includes: 6-12 ounce stackable coffee mugs in cassia collection Fortaluxe superwhite: vitrified china reinforced with alumina oxide or magnesium oxide for durability; glaze, thermal shock and edge chip resistant Cassia collection: beautifully defined, classic shape with a varied plate well for every style of cuisine and portion Featured in the finest restaurants and hotels in the world; restaurant/commercial grade quality Beautiful white color consistent throughout the entire superwhite collection; microwave and dishwasher-safe