With the Admiral Swivel coupler you can mount two tubes at any angle imaginable. A great example of using this coupler would be bracing a truss with an extra tube. Connecting the couplers is much faster and easier than rotating the shackle around the tube and tightening it with a butterfly nut.  
This Swivel coupler has a width of 50 mm and can support up to 500 kg. Available in both silver and black.

Note: Using a safety factor different from the one indicated is at the customer's own risk.