It has been represented to me as being an equi-equivalent (i.e. half the protons come from each) blend of hydrochloric and sulfuric acids. I am guessing it is actually equi-molar as a proton is a proton and having it equimolar means equal amounts of chloride and sulfate added. It is made by a company called Brupaks and from the directions for its use (on their website) you can dope out the normality. They say to remove 160 ppm as CaCO3 (3.2 mEq/L) alkalinity you should use 0.87 cc/L. That means, if you take them at their word that you are going to completely 0 the alkalinity (to pH 4.5 or so) that the strength is 3.2/0.87 = 3.7 mEq/cc i.e. that is is 3.7 N. It is more reasonable to suppose that you will want to take out about 85% of the alkalinity to bring you to a more normal mash pH of about 4.5 in which case the strength would be about 3.1 N. By comparison, 88% lactic acid is 11.6 N and 10% phosphoric is about 1 N (to typical mash pH).
The only advantage offered by CRS ('Carbonate Reducing Solution') is that it makes protons from sulfate and chloride available to the brewer as opposed to phosphate or lactate. Lactate is fine if you are doing continental lagers but for British beers sulfuric and hydrochloric are more traditional.