MK1 Adeptus Astartes Ultramarine

a Space marine in MK or mark 1 power armour previously used by the thunder warriors the predecessors of the current adeptus astartes. it was designed with fighting in a terrestrial environment in mind, it is not fully enclosed, with no means to support the wearer in a vacuum. Only the upper body is powered, due in part to the fact that during the Emperor's Conquest of Terra, ranged weapons were difficult to make due to technological constraints, and so a warrior's upper-body strength was his most important asset.