quote from Wall Street Journal:
Today, we estimate that ISIS has less than a total of 30 working M1 Abrams tanks and howitzers that are either self-propelled or towed behind trucks (based on our knowledge of how the Iraqi army is equipped and what divisions were in the north). These are the weapons that gave the Islamic State the advantage over the Peshmerga in recent firefights. Yet ISIS does not have the highly trained maintenance crews that are necessary to keep these weapons in good working order. The same problem exists for its armored Humvees and Mine Resistant Ambush Protected personnel carriers. Without maintenance, these captured U.S. vehicles and weapons will break down.
edit: Yes, I know that is not an M1A1 in the photo. Thanks.
ISIS also has MANPADS and ATGM weapons, including 9K11 Kornet ATGM, RPG-7 rocket-propelled grenade launchers, and M79 Osa rocket launchers.