As militants with the Islamic State have seized territory and military bases across Iraq and Syria this year, they’ve taken an arsenal of weapons for their use. What exactly they have, though, has remained relatively unclear to the public.

That’s what makes the video like the one above so interesting. Posted on YouTube on Tuesday by a group calling itself “a3maq news,” it shows militants firing an M198 Howitzer cannon. The artillery piece can be towed, and fires 155mm explosive rounds that can travel at least 14 miles, giving the militants a tremendous new capability. It was unclear whether the video was taken in Iraq or Syria, but a translation of the headline on the video indicates it was recorded at a military airport near Aleppo.

The U.S. military appears to be aware the militants possess the heavy guns. A story reported from Irbil, Iraq, by McClatchy last month states that the militants may have seized at least 52 M198 cannons from bases that Iraqi troops abandoned. Additionally, the very first airstrike the U.S. military carried out this month in Iraq targeted what was described as a “mobile artillery piece.” Officials haven’t said specifically that it was an M198, but said it was a towed weapon, prompting speculation it was.

A U.S. artillery officer viewed the video and confirmed to Checkpoint that the cannon shown is an M198, frequently pronounced “M-one-niner-eight” by combat troops. The U.S. military is replacing it with the more modern M777 Howitzer, which was first used in combat by U.S. troops in Afghanistan.

If the M198 in the video is indeed in Syria, it’s part of a trove of combat equipment the militants have brought over the border from Iraq after taking it there. They also have been seen using U.S.-made Humvees in Syria.