SS Taurus Question

I am confused after looking at the Taurus website... There are two stainless versions. First a new one with hardwood grips that is a matte SS finish and medium frame and constructed of stainless steel. Second is the original SS model with black plastic grips, stainless steel finish and a large frame and constructed with steel. Why the difference in construction (stainless steel vs steel) and the frame size (medium vs large) as per website. Both have 5" barrels and weight 38 ozs. I thought at first it was the same gun with different grips, but after reading the website it looks like a different gun. Whats your take...Thanks