It is an old model or a product that we can no longer order at the manufacturer.
Small size: We recommend taking 1 size up from your usual size.
Having previously owned the Nike Air Pegasus Trail GTX 2 and 3, I took the plunge with the NBs after reading the positive reviews. Initial thoughts were positive about the looks, build quality and the excellent protection on the toe box. However, the feel whilst running was no where near as cushioned and responsive as the Nike. Because of this, your feet fatigue really quickly. If I had had these before the Nike they would have been a straight 5 compared to anything else.
I was dubious about purchasing as I have had issues with sizing of new balance in the past (too small) but these are bang on and so comfortable