The inception of the 8.39 ensued from the redesign of the 6.39 model, showcasing upgraded load charts and a noteworthy boost in lifting capacity, elevated by 2 tonnes (4,409 pounds).

For the first time, this machine is equipped with two extension modes, M1 and M2. These two modes give access to two different load charts, to maximise performance in all operating conditions. The standard extension mode, M1, offers the operator the maximum reach and higher load capacities at the maximum height, while M2 mode restricts reach to provide increased load capacity of up to 8 tonnes (17,600 pounds).