made of high strength aluminum alloy material, adjust-able length with automatic locking device. technical Features: 1) product size (L x W x H): Max. Size: 200 x 45 x 6cm, Min. size: 170 x 45 x 9cm; 2)Packing size(1pc/carton): 170x50x12cm; 3)N.W.: 9.5kg G.W.: 10.5kg; 5) Load bearing: less than 159kg