Doughty G-Clamp. Fits Most Bar Sizes. Long Fixing BoltSWL::- :- 40kg Tube diameter:- 48-51mm. “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 clamp