ComStar's Leak Bubbles Yellow is an HVAC and Gas Leak Detector that has set the standard for high-quality and fast-acting leak detectors in the market today! Leak Bubbles Yellow produces large, consistent bubbles. It leaves a long-lasting coating wherever a leak is detected and its fluorescent yellow color makes the leak easy to see under a fluorescent light. This product detects leaks in natural gas, refrigeration gas, nitrogen, air, and C02. Simply apply with the cap dauber and watch fast, even bubbles appear. Leak Bubbles Yellow is perfect for all types and sizes of leaks, even the smallest micro leaks. Leak Bubbles Yellow will not freeze and is perfectly formulated for both high and low-temperature applications and all types and sizes of leaks. Leak Bubbles Yellow is environmentally safe, non-toxic, and non-corrosive.