he “Cartridge Type” R1234yf Universal Dye Injector makes adding dye with the 53223-YF fast and easy. Simply connect the injector to the low side of the A/C system and twist the handle to the next application line. The replaceable cartridge provides 10 applications of universal dye that is compatible with R1234yf systems. While the injector hose comes complete with a R1234yf coupler and adapter fitting. Illuminates leaks through the use of high quality universal fluorescent dye For R1234yf A/C systems Safe or hybrid and electric compressors