This is a Shemaugh made by Rothco.  The size is actually 44 inches square, and this is important; If you intend to use this "tactically", meaning you will wear it tied to form a mask and head covering, you need a large shemaugh.  If it is too small, you will not be able to tie it traditionally.  You can see how this is done if you go on Youtube and search "How to tie a Shemaugh".  I purchased another one from another manufacturer, but it was too small, and much lighter material--this one is heavier, but not to the point of being cumbersome.

Those of you who are unaware, there are multiple uses for these "Arab neck scarves", so don't be worried about being considered a terrorist sympathizer--similar scarves are used by the US military in Afghanistan and Iraq.  They keep out dust, cut wind, contain and absorb sweat, can be "wet down" to cool you by wrapping around your neck, can be wrapped around leaves to fashion a decent pillow, if folded 4 times can filter water (not recommended except if a carbon filter is unavailable-and boil water as well if you can), can be used as a weapon (a Garrote, or you can put a rock or other object inside and swing like a bludgeon), makeshift towel, you can cut two small slits in the material and use to shield your eyes to keep from going snow blind, and it keeps you warm as a neck scarf as well.

The photo description is accurate, it is a dark military green.