Unimogs are available with short wheelbases for implement carrier operations or long wheelbases for all-terrain cargo carrying operations. Currently, Daimler offers the 437.4 heavy series and the 405 implement carrier series. Starting in 1951 having purchased the traditional Unimog from Boehringer, Daimler-Benz started making the Unimog S series in the mid-1950s and added light, medium and heavy series to the model lineup in the 1960s and 1970s, before they successively reduced the available models during the 1990s to end up with the modern implement carrier and the heavy series today.