Colonel Kaehler always had a special interest in bio-mechanics. He was in close contact with the old Mendix OT biomech development centres in Rome Green, and willingly tested any of their new designs in the field. He also suggested improvements on many of their models. The AR-2 is built on a general bio-rifle base, with Kaehler's suggested features on top. It is a simple, sturdy design, but quite expensive to manufacture.