These 2-in-1 stainless steel are designed and engineered by Nine Stars the World's first legal patent holder. With one kitchen size and one bathroom size, you can use them almost any place you want, such as kitchen, office bathroom, dorm room or a kid's room. These two trashcan uses the most advance sensor technology can be found in all Nine Stars trashcans. As your hand or debris within ten inches and 130° angle from the infrared sensor, the lid will automatically opens. The lid will remain open if debris or hand remains within the range of the infrared sensor. Three seconds after your hand moves away from the lid, it closes automatically. Energy saving technology keeps battery life 20% longer in normal daily usage. Required four D-size batteries for smaller can and three C-size or 4 D-size batteries for larger can (not included). Includes an inner plastic bucket (DZT-8-1c) for easy cleaning. The size of the trashcans are 13 Gal. (50liter) & 2 Gal. (8liter).