Check your car for coolant system leaks with the Ring RLD2 Coolant System Leak Detection Dye. Using UV light, the RLD2 dye will be seen clearly, making it much easier to identify leaks. Find leaks you would otherwise miss. Safe to leave in any system. Add to coolant system to detect leaks in water pipes and radiators. One 25ml bottle will do 10 litres of either OAT(pink) / IAT(yellow) automotive coolants. Ring Automotive UV Dyes find leaks quickly and easily. They are safe to leave in any system, so flushing and refilling the relevant systems after leak detection is not necessary unless required to repair the leak. UV light required to show dye leaks.