Contains FJC Universal Fluorescent Leak Detection Dye • Compatible with R134a & R12 • Compatible with Mineral, Ester, Paraffin, and PAG Oil. • Can be detected using any standard UV light. • Saves time over existing methods of dye injection. • An all natural Ester oil, that contains additives which give it the ability to lubricate and protect the system at the same time. • Prevents acid from forming and inhibits corrosion. ATTENTION A partial charge of DyEstercool™ Oil will not provide enough dye for proper fluorescing. Only a full system charge during normal service will provide maximum fluorescing for the mobile A/C system. A partial charge may be added to a system which already contains Fluorescent Dye.