This model is identical to the CR5Z except that it's a hybrid V/bowl shaped cup and it's shallower than the CR5Z. It is ever so slightly deeper than the other commercial Medium cups, so if you need a little more room than the other M cups in the series, this is the one for you. This rim profile is a bit wider than all of the classical models, but not as wide and cushioned as the commercial models. All the inner diameter specs stay the same for each of the models, but the outer diameter increases on all of the classical models, and decreases on the commercial models.