Black Copper Oxide - Cupric Oxide - CuO - 5 Pounds Known as black copper oxide, cupric oxide, or by the chemical formula CuO Particle size runs about 500 mesh (30 microns) Copper oxide is used in pigments, ceramics, batteries, along with a wide range of other uses Shipped in a resealable bag that is sealed for safety and freshness. It includes a tear-off tab for easy opening We sell in bulk for so many different uses, we don't include any specific use instructions