The ZM was a "z" muscle design.  This moved more weight towards the center and deeper part of the club face.  The 710 MB is much closer to the 690 MB design.  The 710/690 is a more traditional muscle back where the center of gravity is a bit higher…

That's great, I was just curious.  As I have seen a few posts regarding the weight kits.  With my new driver, I now have all Titleist clubs in my bag.  I'd been hitting Ping drivers since the TiSi, tried the new 910 D3 and I fell in love!!!  Thanks…

i know because i saw some of the bags and head covers that are released there and they are awesome i would really like to see them released in the states.

Appreciated.