Fluoro-Dye Retro Lube with? MPD? A/C Dye is a 100 Ester / POE based lubricant compatible with most Compressors,Refrigerants and lubricants. It is compatible with 134A, & R-12, systems with mineral, Pag and Ester/POE based lubricants and combined with MPD?? Multipurpose A/C dye you can find the smallest of leaks on any system.