Back in April of 2009, I requested dimensions from the MPower company and Glenda Tutt, the big kahuna there, replied "I currently have one size 65mm incl the stem, 50mm the cup alone, diameter is 42mm."
In other words, WxL = 42x50 (with a 15mm stem.)
But 18 months later in September of 2010, MPower reviews have posted that the actual dimensions are WxL = 47x53 or 47x54, which is a much larger cup.
Have they changed the size of their cups? Does anyone have one of their old smaller cups to compare to the (new?) larger ones?