Silver pry-off bottle caps with an oxygen liner are a nice way to cap your latest homebrew. They can also be used to identify one batch from another.
Made of metal, these caps are designed for use with a capper that forms it onto the bottle to create a good tight fit.
Three Piece Airlock
Cascade Hop Pellets - 1 oz (28 g)
Catalyst Fermentation System
Star San Sanitizer - 16 fl oz (473 ml)