... by screw,and has a high load bearing capacity. •the main tube is 50*3mm,brace si 25*2mm ,besise:•ladder truss ... and good quality of alloy Al-aluminum tube,resonable price can help you save the expenditure•the main characteristic is using of easy ... which is mainly used for movable performence stage,ceremonies,the indoor exhibition ,planes ,the studio,hanging lights,product fairs,exhibition halls display ...