Brought to you by CDI, the same manufacturer of Conserv ™ Safe Coin Solvent, BU Plus ™ is a special rinse for use on coins and other durable objects for the purpose of removing residues and brightening metallic surfaces. This product utilizes a strong caustic base that can be diluted with water if needed and it is always recommended that gloves be worn while handling chemicals. BU Plus ™ can be used on silver, gold, copper, nickel, bronze, and brass coins in circulated, uncirculated or proof condition. Do not use on aluminum. As we like to say, "Because Sometimes We Need It".