The notches allow for stacking, but theres no way Id buy this brand again. You have your own dedicated subwoofer. There is no doubt these are beautiful shoes. This was my game changer for my kitchen. En principio la publicidad es bastante atractiva y podríamos decir que se ajusta bastante a la realidad. Really love these headphones. Based on other reviews, I just purchased this hitch locking pin for an upcoming cross-country road trip. Im pretty sure I know why they would say that though. Id rather have 201ms than 205ms. Assembly was fine, had to kind of guess which bolt or pin to use for a couple parts, not clearly marked.