True Colloidal Gold – 200 ppm in a 500 mL (16.9 Fl Oz) clear glass bottle with a black phenolic cap. This product consists of 99.99+% pure Gold nanoparticles colloidally suspended in pure water. This product may be ruined if allowed to freeze, so make sure not to have this delivered to an outside mailbox, porch, etc. where it may be left in freezing conditions. You are purchasing 500 mL (16.9 Fl Oz) of Sirius Metals manufactured 200 ppm true colloidal Gold in a factory sealed clear glass bottle with black phenolic cap. This product consists of 25 ppm of 99.99+% pure Gold nanoparticles – colloidally suspended in pure water. No color is added. It is made from more expensive 99.997+% pure Gold metal – which is up to 10 times more pure than 24 Karat Gold.