Issued by the Republic of Panama in the early 1970s, this Twenty Balboa proof silver legal tender coin was minted from 129.50 grams of .925 fine silver (which is just under four ounces of pure silver). It has a diameter of 60 millimeters (about 2 7/16 inches) and comes in its original mint issued box with a Certificate of Authenticity. Great addition to any collection of world coins.