What is R&O 150 oil?

[atikovi]

I bought a used DeVilbiss pressure washer and it says to use R&O 150 oil in the pump or if unable to find, use 30W non-detergent motor oil. What is R&O 150 and how much better is it than 30W?

 

[simple_gifts]

http://www.lubeoil.com/pdfs/conoco/industrial-oils/FOB Multipurpose RO Oil TDS Web.pdf

150 is the grade. Page3