A washbasin with a full brass bouncing pop-up waste/drain flow is a type of sink or basin designed for use in bathrooms. The “full brass” construction typically means that the drain assembly, including the pop-up waste mechanism and other components, is made entirely of brass, which is known for its durability and corrosion resistance. The “bouncing pop-up” feature allows you to easily open and close the drain with a simple press or push.