Propper has started several new apparel collections earlier this year with these STL I Pants being a part of the LS1 line. I don't know what any of those abbreviations mean, but the general design theory on the LS1 line is to combine tactical and athletic ideas which seems like a pretty good idea. Overall they fit a good middle point where they don't quite scream tactical man yet have more usable features than the more covert designs.