Clamps 

This catagory has two different types of clamp that we use in our stage lighting rigs.  The individual clamp thats purpose is to bolt onto a fixture and then clamp on to a pipe.  In these circumstances you need to pay attention to the bolt size to make sure the whole in the yoke is appropriate for this clamp and then what size pipe you have and if that clamp will clamp appropriately on to that pipe.  The other sort of clamp on this page is a beam clamp which is a device that enables you to clamp onto an I Beam to create a hanging point. - Louie Lumen