Rock Oil ST90 Gear Oil is developed from the finest base stocks available, combined with anti-oxidants and anti-corrosion additives giving a range of straight oils for a wide range of applications such as spindle lubrication, gear boxes requiring non EP oils and bearing lubrication. Rock Oil ST 90 Gear Oil is a highly stable, long lasting lubricant with a high viscosity index and oxidation resistance providing maximum protection against rust and corrosion. It also incorporates anti foam agents and has excellent water separation qualities.