Larger users put more demand on armrest width, length, height, and stability. Maxis armrests have 128mm of vertical travel and adjust laterally from 400–600mm, wide enough to avoid pinching. The armrest lock stops the arms from splaying outward when you lean on them to sit down or stand up, a stability feature specific to Maxis (the LiberNovo Omni prioritizes armrest flexibility instead, since the two chairs are built for different body types).