Leak Detector Cal Blue(R) LT High Viscosity Low Temp Gas Leak Detector Size 1 qt. Color Blue Temp Range (F) -20 to 220 Characteristics New Advanced Formula Provides Long Lasting Bubbles and the Product Will Remain in Contact with the Applied Surface for an Extended Period of Time. It is Also Noncorrosive to Metal and This is a Significant Feature as it Helps to Maintain the Integrity of Piping Tubing and Fittings. Also It Does Not Effect Ultraviolet or Black Lights.