The Ping Eye 2 BeCu. Ping 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. Ping Eye 2 irons are without doubt the most popular irons in the history of the game. This version - with the softer beryllium copper heads - remains very desirable.