20 oz container of back flush detergent. Puly Caff really eliminates coffee residue and rancid oil in Portafilters, Group Heads, Group Valves and pipes. Puly Caff Plus uses acidic compounds uniquely designed to protect the metal surfaces of your espresso machine. It foams on contact with water and rinses clean allowing quick resumption to coffee making. Puly Caff is NSF approved. Ideal for the maintenance of espresso machines that are back flush capable - But may be used as a cleaning agent for non back flush machines. This stuff really gets your stainless shining again!