The I'limi, K'aili and 'Ahina Mitsubishi shafts are co-engineered by Mitsubishi and Titleist specifically for our 910 heads and you cannot purchase them outside of Titleist.  We co-engineered them using the same MDI technology to fit different swing speeds and flexes.  The tour issue Project X and the Aldila RIP are the standard after market shafts that can be purchased anywhere.  All five of these shafts are stock shafts in our 910 drivers and there is no upcharge. 

Thank You Cathy. It looks like the project X 7.0 for me then.

I would like to know if there is a difference between the titliest co engineered diamana shafts and the one you get from mitsubishi rayon from retail shops

The primary difference between the two shafts is torque.  Our shafts feature progressive torque values that decrease as the flex gets firmer so our X flex shaft is very close to the X flex after market shaft.  Both shafts use the same materials and the MDI (multi-dimensional interlay) technology.  Our testing has shown progressive torque values to work better for the varying swing speeds of our players.  Players with tour speeds typically use X flexes with low torque because of how fast they swing and how hard they load the shaft.  The low torque provides them with more consistency and control.  Players with moderate to fast swing speeds typically fit into R and S flexes.  The higher torque value in these flexes provides them with better feel and improved timing.