Celtic Knot Flask with Secret Cup It's nice to share--but it's nicer to have your own. Here's your Celtic Knot flask with all the great features of stainless steel construction, secret built-in shot glass, and the option of your authentic Irish coat-of-arms engraved on the side(see item #2559 for coat-of-arms). The other side is still a bright brass Celtic Knot that conceals a secret stainless steel shot glass. The perfect gift for everyone just got a little more perfect. 8 oz.