See: Hiro-Seiko Hiro Seiko have introduced a new line of high viscosity differential oils. They feature an excellent viscous resistance and are water-resistance, acid-resistance, alkali-resistance and anti-dust. These high viscosity differential oils are available as 100,000cps, 200,000cps, 300,000cps, 500,000cps and 1,000,000cps.