developed primarily for use as a topol icbm mobile launcher, the 7912 model is similar in design to the maz-547a but has seven axles instead of six, including one dead axle. in the mid-1980s, the maz-7917 variant was introduced, with an additional length of and crew cabins similar to the maz-7916 - and at present, the 8-axle mzkt-79221 variant is used to carry the topol m, topol's replacement.