Pierre Boulez: Repons 2 Cd Inc. Headphones Binaural Mix

Pierre Boulez: Repons Ensemble Intercontemporain cond.
Boulez and Dialogue de l ombre double played by Alain Damiens .
This is the normal DGG CD but also includes an extra disc - the same recordings in a headphones mix in a plain paper sleeve .
This was a limited edition I believe, sent after I cut out and sent in a coupon which was attached to the CD booklet.
Very good condition, discs are unmarked.