For use with electrovoltaic cells or in various other chemical, physics and electricity experiments. Each metal electrode measures about 5″ x 3/4″ x 3/64″ ( It is 12cm x 2cm x 1.2 mm in metric system). Carbon (graphite) is 5 mm (1/8″) thick.This is the second most complete collection of metals offered by MiniScience. All metal electrodes are stamped with 2 letter identification code for easy identification.WARNING: Metal electrodes have sharp edges and can cause injury. Not a toy!. Handle with care. This set include Aluminum, Brass, Copper, Iron, Lead, Zinc, Carbon, Bronze, Stainless Steel, Magnesium, and Nickel. Each electrode is stamped with a two letter identifier code.