Originally Fox used blue 5wt shock oil in all their standard shocks and JM92 red 7w "racing" oil in their race series shocks. Now all modern Fox shocks come with JM92 red 7w oil as of about 2014.

If you have an "emulsion" shock without a reservoir, you fill the shock body to Fox's specifications and measure from the edge of the body down to the fluid.

If you have a shock with a reservoir, you fill the shock body to Fox's specifications and measure from the edge of the reservoir down to the piston.