A 15mg ampoule of Potassium metal sealed under argon.  Purity is 99.99%.  The metal inside is shiny and oxide free but the yellow color is due to the color of the glass itself.  These will fit nicely inside a 5/8dram vial and one will be included with every purchase..  They are the perfect size for collectors who want a small sample of this reactive metal.  Sorry no international shipping (International buyers, your order will be cancelled if it contains this item or any one of the following: Arsenic, Cesium, Chlorine, Bromine, Gallium, Lithium, Mercury, Rubidium, Sodium, Thallium, Thorium, Uranium, Amorphous Phosphorus, White Phosphorus or the Complete Element Set)