How can I know what is # in equation?

I am trying to find the solution by using Reduce to fit my data with FindFit. And I don’t know what # in the result equation. My code is:

Reduce[kh == (oh (0.2 - 2 (0.5 (ohmax - oh))^2))/(    ph2o*po2^(1/2) ko (0.5 (ohmax - oh))^2) && kh > 0 && ph2o > 0 &&    po2 > 0 && ko > 0 && oh > 0, oh, Reals] 

And I get this result: result1

I need to put the result equation into the FindFit however, I don’t know what # means and how I should modify the equation so that I won’t have any issue with FindFit.

Thank you.