Although unused, the bowls have scratches due to being stored in a stacked state. Please be aware of this. Sizes available are 15cm, 18cm, and 21cm. These stainless steel bowls are supervised by Chef Koyama, the owner-chef of the famous patisserie "Patissier eS KOYAMA" in Sanda City, Hyogo Prefecture. The "GOOD AIR IN BOWL" is characterized by its unique, enclosing shape. The bottom is small, making the width narrow, and it has a deep design. This shape is similar to the mixers used by professionals, preventing the batter from spreading thinly around the entire bowl, allowing for thorough and even mixing, which makes it easy for air to enter and results in high-quality batter. Therefore, even with a small amount of egg yolks, such as for a single layer of a separate-method roll cake, it can be whipped sufficiently. Furthermore, these bowls are design-registered with the Japan Patent Office. They are a unique bowl created by Chef Koyama. With conventional deep bowls, the height may not be sufficient, causing the batter to splatter. When using a hand mixer, the batter will splatter if you start whipping at high speed. This bowl has a carefully considered height, allowing you to whip at high speed from the beginning without splattering, and then adjust the speed as needed. The GOOD AIR IN BOWL can also be stacked. This is a great feature for saving storage space.