Its just a standard 1980's hot weather service/field cap. Used throughout the USSR, nothing special or odd about it ( i.e. had nothing to do with troops in Syria, though they might have had them too).
How many models of such caps existed? I have seen 3:
with removable "mask", with "mask" attched (sewn) permanentlyand with "mask" removable from a neck cover that was attached permanently. All dated late 80.!
Was this just a question of factory mistake or what?
I couldn't find much reference on that.
and btw. Didn't they use a bit lighter-coloured uniforms in Syria?