Titleist 907 D1 driver. New for 2007, the Titleist 907 driver is the No 1 460cc driver on the PGA Tour. There are two models - this model, the 907 D1 which is slightly triangular in shape and is aimed at all golfers - and the 907 D2 which has a more traditional shape and is aimed at more serious players. Both have face angles which are square (not slightly closed or 'draw-enhanced' as many other drivers are). The Titleist 907 D1 driver is a multi-material 460cc driver with a high moment of inertia (MOI) for increased distance with forgiveness and outstanding playability. MOI is the clubhead's resistance to twisting on off-centre impact (i.e., heel, toe, etc). A higher MOI value means more resistance to twisting. The benefit of a higher MOI is longer distance (better energy transfer from club to ball) on off-centre hits. The Titleist 907 D1 has been designed with a multi material design, including a 9SP700 beta Titanium face insert for a responsive thickness and a lightweight aluminium hosel which frees up clubhead weight so it can be redistributed low and deep.