Stoughcool's semi-synthetic coolants are formulated with the most advanced chemistry using new technology to provide excellent machining performance while keeping machines clean and are operator friendly. Like all Stoughcool products, our semi-synthetics run very clean and have excellent sump life with outstanding biological control. Utilizing our C80 Shield Technology, our products resist bacteria providing a clean sump and no bad odors! Our semi-synthetics also are formulated with our "Jet Fresh" scent providing a fresh clean scent in every shop.