The Swedish 120-mm Self-Propelled Mortar Granatkastarpansarbandvagn 90 is also known by the names Grkpbv90 and Mjölner.

The Mjölner mortar system mounted on the tracked chassis, designed and manufactured by BAE Systems Hägglunds, will increase the capabilities of the mounted fire to support mechanized battalions. This allows the army to use features well adapted for installation on various mobile platforms.

Mjölner is the name of the hammer of Thor in Norse mythology.

On December 23, 2016, the FMV (Swedish Defense Procurement Department) issued a contract to BAE Systems for 575 million kroner (68 million dollars) for the supply of 40 self-propelled Grkpbv90 (Mjölner) 120 mm Self-Propelled Mortar systems to the Swedish army on the CV90 Infantry Fighting Vehicle chassis. The system was developed by order of the Swedish army by the Swedish units of BAE Systems as a replacement for the 40 units of the automated 120-mm double-barrel mortar AMOS systems previously planned for purchase for the ground forces, also based on the CV90 infantry fighting vehicle.

The artillery part of the system was developed by BAE Systems Bofors, and BAE Systems Hägglunds is responsible for its integration on the CV90 chassis.

Mjölner is a turret with two 120-mm smooth-bore mortars mounted on a CV90 chassis. The gun has a semi-automatic loader, which allows a reliable mechanical system to quickly and reliably load it in any combat conditions. Mjölner has an azimuth angle of 60 degrees without the need to rotate the tower. With vertical guide angles of 45 to 85 degrees, targets can be effectively hit over a wide range of distances. Conventional 120-mm mines with a range of up to 9 km are used for firing.

Mortars are placed in a rotating steel armor turret, and the turret rotation is carried out only by manual. The total weight of the turret is 7 tons. The 50 firing ready rounds is at the rear of the turret, manual feed is possible, there may be an additional ammunitions in the vehicle hull. The crew of four people - the commander, a driver and two loaders.

The first prototype demonstrator Grkpbv90 (Mjölner) was manufactured and delivered over for testing in October 2017. In February 2019, the first four pre-production systems out of 40 ordered by contract were delivered. IN the 36 serial systems, the first four must be delivered in August 2019, and then four units must be delivered every two months, with deliveries completed by the end of 2020.