Product description the revolutionary pentagonal profile of our largest diameter flatso increases stroke consistency due to its wider flat front and multiple edges the new flatso 3 0 with counter core technology lets the golfer fine tune the feel and stability of the putter by adjusting the weight of the grip every new counter core putter grip comes with a 50g back weight that engages larger muscles in the arms shoulders and back which results in more of a pendulum motion our patented no t