KU100 is for use in only Kosmic Klear UC1, UK Kosmic Kandys, and UB Kosmic Urethane Enamels. KU100 must be mixed with the products having UC1, UK, and UB codes before use — caution: not to be mixed with any other product codes. Due to its unique chemistry, KU100 should never be substituted with other brand catalysts, and this product must be mixed with other products before use. It’s a multi-purpose national rule catalyst for urethane finishes, specifically designed to provide proper cross-linking with HOK resins, giving excellent chemical, fuel, and water resistance