The Gravity T-Bar facilitates mounting two loudspeakers on a single stand. It is made of heavy-duty steel with a black powder-coating finish and securely attaches to all 35 mm poles. Width is fully adjustable from 31 to 49 cm.
This thing does what it's supposed to do and does it well. I have no complaints so far. I like how you can put the Allen key to its own little compartment at the end of the t-bar, so you won't lose it.
I use this one with K&M stands.