... pulley system Aethetic, durable, good quality, competitive price Aluminum garden umbrella with crank and single pulley system1. Item NO.: MYSS-0182 ... . Umbrella size: 300mm/6/38 3. Material: Umbrella Pole: Aluminum with dia. 38mm; Umbrella Ribs: 12*18 steel ribs ... free to contact with me, welcome to inquire. Aluminum garden umbrella with crank and single pulley system