The black mylar Rx bags are a safe and secure way to transport your medications. These smell proof bags are completely black all the way around so contents cannot be seen. The bag also features a hole on the top so items can be easily displayed at the register on a display rack. This mylar zip bag can quickly be closed using the zip function or can be heat sealed to make them child resistant. Thanks to the unique lamination process, these mylar bags can withstand the harsh freezing and boiling temperatures. Measuring 4.5 x 4.5 inches, this black mylar Rx bag will hold approximately 2.0 grams of medication.