Medium Duty II(B) Rack Locked by butterfly hole structure and cargo dead weight, layer bearing capacity than duty I（A）; easy assembly and disassembly; limitless connection to main auxiliary rack; enhanced rack robustness; save investment; layer plates arbitrarily adjustable at 75mm steps; steel, wood and other layer plates can be used; Rack consisting of column disc, crossbeams, layer plates, safety pins and plastic footing. Parts: upright poles, layer plates, crossbeam, cross bar, bracing, safety pins, limiting nails etc . Material: Q235 Max load capacity: ≤500kg per layer Specification: