And so what? (about C-400 or C-300 that are difficult to distinguish in such photos)
A conventional air defence system, and it's a normal practice in Russia to deploy such toys near significant air bases (or a cluster of them).
The question is what they are for in Syria? The explanations such as "to remove airplanes that jihhadists may take (from whom?) and send as kamikadzes to the air base" make me laugh. IMHO, just an unnecessary move to show more teeth to US & Co. Looks not so much productive in the situation when both sides (read, even short-sighted politicians) started talking on many issues (coordination on ISIS targets, measures to avoid accidents in the air, sorting out "acceptable" and "bad" Syrian opposition) including cooperation on investigating the A-321 crash in Sinai.