Nu-Calgon 4316-76 Emkarate RL68HP Refrigeration Oil is a synthetic oil designed for use in refrigeration systems. It is a high performance oil that is designed to resist corrosion and wear. This oil is also designed to provide long lasting performance in your refrigeration system. Nu-Calgon 4316-76 Emkarate RL68HP Refrigeration Oil is a synthetic oil designed for use in refrigeration systems. It is a high performance oil that is designed to resist corrosion and wear. This oil is also designed to provide long lasting performance in your refrigeration system.