The Weekend Brewer Stainless Steel Carbonation Cap (1pk) EASY HOMEBREW CARBONATION. Force carbonate your homebrew in standard 2L bottles with this carbonation cap. Much cheaper than kegging and much easier than bottling. SELTZER WATER. Also great for making selter water at home without the need to purchase a carbonation machine. STAINLESS STEEL is stronger and more sanitary than plastic caps. Does not include CO2 tank, regulator, or gas line. This listing is for 1 cap