Jeweler's Gold Testing Pieces-14 Karat Acid Test Solution Easy to Use Enables you to test jewelry, coins, scrap and more... on the go or at home Includes one bottle 14k test acid, and one glass pro-stone, Each bottle contains 1/2 fluid ounce (0.5 fl oz) liquid; will last many uses Test stone effectively acquires sample and does NOT damage the gold you wish to test Very easy to use... ideal for professionals and hobbyists of all ages