Red Line's ShockProof Gear Oil features a unique lubricant containing a suspension of solid microscopic particles as an extreme pressure agent--unique solid dispersion which cushions gear teeth to help prevent tooth breakage and allows the use of lower viscosities. Acting like a liquid grease, the viscosity characteristics of ShockProof Gear Oil allow the lubricants to resist throw-off and provide the protection of a greater film thickness with relatively light fluid viscosity, offering a "best of both worlds" balance of low drag and superior protection. ShockProof Gear Oil products work in a variety of differential and transmissions, however, should not be used with pumps, filters, and with small lines--these fluids are designed wet sump or splash type lubrication. The Red Line Heavy Weight ShockProof Gear Oil is recommended for heavily-loaded racing differentials and transmissions, Off Road racing and problem gearboxes. The viscosity characteristics allow the lubricant to resist throw-off and provide a film thickness similar to a 75W250 grade, while providing the same low fluid friction as an SAE 75W90.