The King F9 SpeedBack One Length irons are a combination of tungsten weighting and innovative shaping to deliver the most powerful and stable COBRA iron. Also features The One Length ™ Configuration that’s engineered with a matching 7-iron length, lie and swing weight specifications. This configuration simplifies your game by reducing the variability in your swing for increased confidence and consistency. These irons are forged E9 Pwrshell™ Face Technology that offers a thicker face design that’ll expand the sweet zone for a higher launch and faster ball speeds across a larger area on the face.