Standard Hook Clamp. 40Kg Safe Working Load. Use with 48-51mm TubesSWL: 40Kg Tube Diameter: 48-51mm Weight: 0.32Kg. “T-bar” clamp for fixing lighting to trussing or other bars. Will fix to bars up to 51mm in size. The long bolt will secure to most bars.. doughty fixing-doughty trussing-doughty hook