This is a common question and unfortunately is due to manufacturer marketing issues. Allergan has appropriately named their implants low, moderate and high profile. The difference between each is the base diameter and the projection. Low profile implants have the widest base diameter and least projection where as high profile implants have the most narrow projection and most projection for the same implant volume. Unfortunately, Allergan gel implant volumes are strange, 286cc, 304cc etc.Mentor's first implant was really a low profile implant based on base diameter and projection. When they introduced a "true" moderate profile implant they had a marketing problem-what to name it. So they named it the moderate profile plus implant. So this implant is equal to Allergans moderate profile implant. Since the introduction of this implant Mentor has changed the name of the original "moderate profile" implant (remember it's really a low profile implant). The newest name is the Mentor Moderate Classic Profile implant. The long and short of it is that Allergan's moderate profile = Mentor's moderate plus. High profile are the same for both. The only other difference is that Allergan implants, for the same volume, have just a bit more projection.It's all a bit confusing so you'll need to have a detailed sit-down with your surgeon.