Syrian rebels have created their fair share of DIY weapons throughout the civil war that's lasted four years and counting. But opposition fighters are especially proud of one: the Jahannam (Hell) Cannon.
What makes this cannon special is the propane gas cylinder, which the rebels say provide a new kind of firepower no other makeshift weapon in the conflict had accomplished so far.

They're so proud of it, in fact, that they created this ad for it.

Here's a translation provided by Brown Moses Blog:
Name: Hell
Function: Explosive barrel Cannon
Specifications:It can fire more than fifteen types of shells that weigh more than forty kilograms. It also has two locally-made rocket launchers (Rohingya).
Range: 1.5 kilometers.
Effectiveness: Up to 200 square meters.
Projectile: Propane gas cylinder.
Cost of the shell: 15000 Syrian Pounds.
Country of Origin: Syria
Manufacture: Ahrar Al-Shamal Battalions.
It first appeared in the conflict in 2013 being used by Ahrar al-Shamal Brigade, an Aleppo-based Syrian rebel group with ties to the Muslim Brotherhood. The weapon was quickly adopted by other opposition groups and now commonly appears on YouTube.
Here's a video of the Hell Cannon in action:
By Hayat Norimine