Sturdy but lightweight plastic bar that I bought to experiment with small condensor mics in various configurations (ORTF, XY, 20cm parallel) for recording my grand piano. Works very well for this, includes very handy markings to make your setup reproducable each time. Also reduces the amount of stands and the general clutter in the area of the piano :-)
Contains an adapter so it works with two sizes of microphone stands (5/8 and 3/8)
I think it is a little expensive for what it is, but there seems no good alternative, so I would buy it again!
ps Note that max spacing for the mics is about 20cm.