Navistar Defense says it has developed a tractor version of its MaxxPro armored truck and added an ambulance kit for existing units.

Navistar is showing the products this week at the Association of the United States Army's annual meeting and exposition in Washington, D.C.

Since 2007, the company's family of MaxxPro Mine Resistant Ambush Protected (MRAP) vehicles has grown to include 11 different vehicle variants. The first six of these variants were developed in only 18 months, said Archie Massicotte, president of Navistar Defense.

"Our ambulance kit, which has received positive reviews from the U.S. Army medical department, can quickly turn any MaxxPro vehicle into a fully functioning ambulance and aid station - with full protection for both medics and patients," he said. "The kit does not require new vehicles. Thanks to the flexibility of our proven truck platforms, we are able to quickly develop new vehicle solutions as well as vehicle variants like the MaxxPro tractor."

Ambulance kits include an easy-to-use litter assist system as well as a protected work space for medics and patients. This, paired with the company's DXM independent suspension, helps medics navigate rough terrain to get where aid is needed. The kit can be installed in many MaxxPro truck versions.

The MaxxPro MRAP tractor uses up-armor kits or MRAP-level protection, allowing two- to three-man crews to carry out support missions. The vehicle is powered by a MaxxForce D13L engine. Two other MaxxPro utility variants, the Cargo and the Recovery Vehicle, are also available. All three vehicles utilize MaxxForce D engines and heavy duty chassis.

To date, Navistar has produced more than 7,500 MaxxPro units, and has retrofitted 1,222 MaxxPro trucks in Afghanistan with its high-mobility DXM independent suspension. The MRAP trucks are in operation with American forces and six coalition forces.