The Blumlein mast allows two figure 8 microphones to be placed "nose to nose" for stereo recording. Blumlein stereo listened to through headphones is very satisfying and realistic, and ribbon microphones exhibit good "classical reach" without loss of bass.
The Mast ($39.00 + shipping) is also available for those who already have Naked Eye ribbon microphones, as it accepts the same low diffraction rotary mount that comes with every Naked Eye mic.
You don't need to use it vertically. In fact, it seems to be at its best (for my non Blumlein purposes) at the end of a boom, for holding a couple of Naked Eyes turned just so at different parts of the instrument. I play the shakuhachi, which is a traditional Japanese end-blown flute, and that can be a difficult instrument to record, as it can sound too dry, too raspy, too bright, etc. depending on mic placement. The ability to back off a bit, which is something ribbon mics can do because the reach or sweet spot is extended out a distance compared to, say, a 1" condenser, and to aim two similar mics while in the playing position, is a great convenience.
By the way, the mics here are not Naked Eyes, but two new Crowley and Tripp mics undergoing evaluation.