Ping Eye 2+. The Ping Eye 2 started the revolution in perimeter weighted clubs. The deep cavity allowed weight to be distributed around the outside of the head - resulting in a high moment of inertia (MOI). In simple terms, it meant the clubhead resisted twisting at impact on off-centre hits - so it was - and remains - very forgiving. Still highly useable, Ping Eye 2 irons are without doubt the most popular irons in the history of the game. So enduring is their appeal, they are still available to buy new from Ping as a special order.