This set contains 15 different elements - Copper, Silicon, Iron, Zinc and Tin(set #1) Titanium, Aluminum, Sulfur, Manganese, and lead (Set #2) Cadmium, Bismuth, Magnesium, Antimony and Carbon (Set #3). Each glass vial contains approximately 20-30g of each element. The glass vials are 30mL in size with black plastic caps. These sets are held by 1/8" clear acrylic holders with rubber feet. Included are 15 element cards describing the elements. They are business card size and laminated 5 mil. The purity of each element is greater than 99%. These are real elements not imitation. These are beautiful sets which will last a long time if properly cared for. This product was designed, engineered and manufactured by teachers for teachers in the United States by Mercury Manufacturing of Texas. A teacher owned company.