The Fadjr-3 240 mm (12-round) Artillery Rocket System (ARS) was developed by the Shahid Bagheri Industries division of the Aerospace Industries Organization of Iran and uses the same chassis as the Fadjr-5 333 mm (4-round) artillery rocket system.

The Fadjr-3 artillery rocket system is based on a modified Mercedes-Benz 2624 series (6 × 6) truck chassis with the diesel engine and fully enclosed cab at the front. To the immediate rear of the cab is a small crew compartment. When launching rockets the cab windscreen would normally be protected by shutters.

Mounted on the rear of the chassis is the turntable with the manually operated elevating and traversing mechanism on the left side. The Fadjr-3 has a total of 12 240 mm diameter rocket launcher tubes in two layers of six with launcher elevation being from 0 to +57° and with a traverse of 90° left and 100° right.

It launches a solid propellant 240 mm rocket with fins that unfold after launch and the rockets can be launched with an ambient temperature of between -40 to +50°C.

The Fadjr-3 unguided artillery rocket system has a rate of fire of one rocket every four or eight seconds and replacement Fadjr-3 rockets are packed three to a crate which weighs 1.65 tonnes.

To provide a more stable firing platform four stabilisers are lowered to the ground before the rockets are launched, two of these are positioned at the rear of the vehicle with another one between the second and third axles on either side.

The rockets can be launched singly or in ripple fire and once the launcher has expended its rockets it would normally deploy to another position when new rockets would be loaded using a crane. To help avoid counterbattery fire the Fadjr-3 would redeploy to another area for reloading once the 12 rockets had been fired.

It is possible that some of the technology of these rocket systems could have come from North Korea.

When first observed in 1996, this system was installed on a Japanese Isuzu (6 × 6) truck chassis and these were deployed with Hezbollah units operating in Southern Lebanon.

It is assumed that these unguided rockets have a high-explosive warhead, although other types of warhead are considered possible.

It is considered probable that these systems will be installed on a new forward-control chassis which is already used for the latest Fadjir-5 system.