The Radium graphics kit is based on the chemical element with the symbol Ra, and atomic number 88. When exposed to air, it bonds with nitrogen instead of oxygen, causing it to form a black layer of radium-nitride. All isotopes of Radium are radioactive. When radium decays over thousands of years, it develops a fluorescent glow called radioluminescence. We think that's pretty awesome. You learn something new every day….or if you want that mud splat theme, look no further! This design makes for a perfect combination. Comes as a complete kit to do both sides of your rig.