manufacturer for various scaffolding couplers. swivel coupler material :SPHC thickness: 5mm surface:self-color, zinc plate swivel coupler-pressed type1,material :SPHC 2,Standard:EN74 3,for tube o.d. 48.3mm x 48.3mm 4,thickness: 5mm 5,weight: 1.05kg 6,surface treatment: zinc plated,passivated,electroplate7.Color:Self-color(Black) , White, Yellow pressed swivel coupler