STERLING HEIGHTS, Mich. (AP) — General Dynamics has won a $134 million Army contract for work to improve up to 550 Stryker combat vehicles.

The eight-wheel-drive Stryker built by General Dynamics is in use in Iraq and Afghanistan, and the contract includes design, engineering and production work to update and enhance the vehicles after they return from combat duty.

The “design and engineering work and enhancements” on the new vehicles will be done in Sterling Heights, Mich.; as well as Anniston, Ala.; Lima, Ohio; and London, Ontario. The company said in a statement it expects to complete the tasks by June 30.

General Dynamics already has delivered nearly 3,000 of the vehicles and has trained more than 19,000 soldiers how to use them.

The armored Stryker can travel more than 60 mph on highways, has a range of 312 miles, and is designed to protect soldiers against improvised explosive devices, rocket-propelled grenades and other weapons. Ten versions of the Stryker are used for troop transport, medical evacuation, combat or other duties.

Shares in the Falls Church, Va.-based defense contractor closed Friday at $68.24, down 27 cents, or 0.39 percent.