Features: 1) Aluminum argon arc welding 2) Solid construction and safe 3) Easy to assemble Features: 1) Aluminum argon arc welding2) Solid construction and safe3) Easy to assemble4) Suitable for assembling lights, AV frames on stages and other exhibition places5) Models and length:a) Section 300 x 300 length (mm): 600, 900, 1200, 1500, 1800, 2100, 2400, 2700, 300b) Section 450 x 450 length (mm): ...