This is a set of thigh extenders for the Transformers Generations: War for Cybertron - Siege Leader Class Ultra Magnus figure. These extenders increase his height so that he is closer in height to Leader Class figures from the Prime Wars Trilogy and other Previous Generations figures. This also adds a bit of length to his vehicle mode as well.
Hammer seen in pictures 2 & 3:
Axe seen in picture 4: