In 2012 500 M-Series frame size introduced. Five models offered, with operating capacities ranging from 1650 lb. (model S510) to 2100 lb. (model S590), and engines rated at 49 hp (models S510, S530), 61 hp (models S550 and S570) and 66 hp (model S590).
WheelsAge.org '2005–pr.