Excellent Half Coupler/Truss Clamp, very good load carrying capacity SWL 100kg, is very easy to tighten thanks to the large thumb screw nut, much better than a wing nut. The fact that the M8 screw goes through the thumb screw means you're able to undo the thumb screw a long way without it dropping off, making easy to fix onto truss. Very EASY to use, very good value too.