Unlike traditional V60 drippers with which coffee is extracted through the constant pouring of hot water, this dripper is specifically made for immersion extraction. The metal ball placed at the base of the dripper blocks water from flowing through, allowing the poured water to stay inside the dripper for 2 minutes. Then, with the push of a button, the coffee flows down into the coffee cup, allowing for easy, even coffee extraction. Both the 02 and 03 sizes come with a 40pc pack of the corresponding size paper filters. The Server Set comes with the 02 size dripper, 40pc of 02 size paper filters, and a 300ml glass beaker server.