Function: It is a manual press designed to extract juice from fruits like oranges, limes, and other citrus fruits.
Material: The packaging indicates the surface is treated with "innoxious material". Search results suggest such devices are often made from materials like stainless steel or aluminum, which are corrosion-resistant and do not react with fruits.
Design: The press shown in the image is a type of hand press juicer with a handle mechanism for applying pressure to the fruit.