The Protectron is a medium-sized, humanoid robot with a bulky, utilitarian design, featuring a rounded torso and head mounted on a thick, central column. Its arms are segmented with visible joints, ending in simple, clamp-like hands, and its legs are sturdy with wide feet for stability. The surface is primarily metal with a worn, slightly rusted texture, showing signs of weathering and battle damage, and it has a distinctive, single red eye sensor. The color scheme is muted, with patches of faded yellow and blue paint, indicative of its pre-war origins and subsequent neglect.