Ladder hooks of metal; ladder supports of metal; mobile steps [ladders] of metal; stair treads [steps] of metal; stringers [parts of staircases] of metal; centre poles of metal for staircases; aluminum ladder rungs; handrails of metal for stairs; metal stepladders and ladders; ladders of metal; steps [ladders] of metal; step stools of metal; ladder stand-offs of metal; metal retractable ladders; metallic motorized retractable ladders.