The 122 mm HADID rocket launcher system is a 40-round launcher assembly system mounted on the rear of a Mercedes-Benz 2624 (6 × 6) truck chassis. These chassis are also used for the Fadjr 333 mm (4-round) and Fadjr 240 mm (12-round) artillery rocket systems that are covered in a separate entry. The technology has certain operational characteristics that are similar to the NORINCO (China North Industries Corporation) 122 mm (40-round) Type 81 MRS and the Russian 122 mm (40-round) BM-21 systems, both of which are covered in detail in a separate entry.

The launcher assembly has two banks of 20 122 mm barrels in a side-by-side 4 × 5 row arrangement and is mounted on a rotating cradle fitted to the rear of the truck. The unguided rockets are spin stabilised and are of the 122 mm type. The full 40-round load can be salvo-fired in 20 seconds, with the firing operations conducted either from the vehicle cab or from a ground position situated at a safe distance from the launcher. Reloading is performed manually by the launcher crew. The sighting system is mounted on the left side of the launcher at the rear.

These rocket systems have been developed by Aerospace Industries Organization Shahid Bagheri Industries. Details of the Iranian 122 mm ARASH artillery rockets are given in a separate entry. These can be fired from any 122 mm rocket launcher.

The actual launchers have been developed by the Armament Industries Division of the Defence Industries Organisation. The launcher has also been referred to as the Hadid 122 mm (40-round) HM20 multiple rocket launcher system.

This facility also manufactures tank (for example 125 mm) and artillery (for example 122 mm, 152 mm and 155 mm) barrels.

A copy of the North Korean 30-round 122 mm calibre BM-11 rocket launcher system has also been produced. This comprises a single bank of three rows of 10 tubes mounted on a rotating cradle assembly. The chassis used is the Mercedes-Benz LA911B (4 × 4) truck chassis. Four stabilising jacks are lowered for firing and a hydraulic crane unit is also fitted immediately aft of the cab for use in reloading the rocket tubes.

The rear stabilisers are lowered to the ground manually while those to the immediate rear of the cab are lowered to the ground using an hydraulic system. It is possible that the launcher is fitted with an auxiliary power unit.

This has been designed for installation on boats and rafts and has two banks, each of eight 122 mm launcher tubes. This is designated the HM23.

An 8-round launcher assembly has been produced for use on naval vessels. The total launcher weight is 450 kg with the system having a maximum range of 14,000 m. Elevation range is 0-20°. The standard 122 mm rocket types are fired from the 3 m long, 23.4 kg weight barrels.

A man-portable single-round 122 mm calibre rocket launcher has been produced. Mounted on a tripod the system has a maximum range of 20,400 m, an elevation range of 5-50° and a traverse of ±12°. The total assembly weighs 85 to 90 kg and uses the standard 3 m long, 23.4 kg weight barrel. This is designated the HM21.