I use four of these clamps on my scanners. They are solid and fit well onto the small form factor truss. I would have liked to see the nuts and bolts to go with them but apparently its normal for Doughty to miss this out. The hook clamp is relatively small and the distance between the fixture and the thing your hanging it on is kept to a minimum. This is perfect for when you need your lights to be as high as possible. My band sometimes play at venues with low ceilings so this has worked out well for me. These are small but they are strong, I expect nothing more from Doughty! Remember to check the ratings of this clamp with the weight of the fixture you want to rig.