Elba ERTC Series lubricants are designed exclusively for semi-hermetic (piston) Compressors requiring a POE-type lubricant for improved miscibility with the refrigerant and improved oil return to the compressor. Semi-hermetic compressors are used in many supermarket applications and commercial (mobile) refrigerated trailer/truck applications. Elba ERTC Series is available in five viscosity grades for HCFC & HFC refrigerant gases like MO99, R22, R134a, R401a, R401b, R402a, R402b, R404a, R407a, R407c, R408a, R409a, R410a, R422a/d, R502, & R507c. Summit RTC Series Employs a unique base fluid that provides optimum refrigerant solubility/miscibility.