B stock are new products that a company sells at a partial discount due to minor cosmetic flaws. You can get discounts on a lot of electronics this way. Regardless, even paying full price the Atom DAC is worth it and JDS has the best customer service I’ve ever seen from a company. I had a Schiit Modi previously but sold it because the Atom+ is one of the few DACs that works seamlessly with the PS5 (with their adapter cable).