The video shows the Martyrs of Mheen Brigade unloading 13 covered tubes. The markings on the boxes they are uploading from have been purposely and systematically obscured
The items are described at "Red Arrows" in the video, the name used for Chinese HJ-8 ATGMs (Anti-Tank Guide Missiles) , and it's possible to determine the exact model thanks to the coverings on the rockets
As per Ares Arms Research Services' earlier post on Chinese ATGMs in Syria, the letter "E" in a circle indicates these are HJ-8E models, the same type reportedly supplied by Qatar earlier in the conflict, which also had their markings obscured.
The earliest posts on the Martyrs of Mheen Facebook page suggests they have been active in the Qalamoun region since October 2013, and videos posted to another YouTube channel associated with the group show they have access to Croatian RAK-12 multiple rocket launchers, supplied to opposition groups aligned to the Free Syrian Army in early 2013 by Saudi Arabia, smuggled via Jordan into the south of Syria.
It's very interesting that the same group have access to the Croatian weapons provided by Saudi Arabia and these Chinese HJ-8E ATGMs, fresh supplies of which have been rumoured to have entered the south of the country in recent weeks. Could the HJ-8Es in this new video be the first signs of large quantities of this new supply arriving in Syria?