For use with electrovoltaic cells or in various other chemical, physics and chemistry experiments. Each metal electrode measures about 120mm x 18mm x 0.75mm (5″ x 1/2″ x 1/32″). Metals collection includes: Iron, Copper, Zinc, Aluminum, Steel and Magnesium.. WARNING: Metal electrodes have sharp edges. Not a toy!. Handle with care. All electrodes are stamped with 2 letter codes for easy identification.