For Tubes 48-51mm in Diameter. M10 Light Fixing. 500Kg SWL. Black or Silver FinishSWL: 500Kg Tube Diameters: 48-51mm Fixing: M10 Dimensions: 116 x 110 x 50mm Weight: 50g. Half coupler for 48-51mm tubes with M10 fixing. SWL 500Kg. half coupler-coupler-lighting clamp