Traditional opaque white “milking” lubricants are actually a suspension of mineral oil and other agents. Such products are typically labeled to “shake before use” because over time the ingredients will separate out into layers. In a larger container of 15 gallons this will produce uneven lubrication effects as the various layers are accessed by the uptake tube. Of course it is impossible to shake a 15 gallon drum to re-distribute the ingredients. ProLube is a true solution and is totally clear. It will not separate and provides even and consistent lubrication action throughout the use life of the container.