Mizuno jpx900 forged golf irons use boron infused steel to give you higher balls speeds without losing the feel of a forged iron mizuno has used two types of technology in their new iron a new milled pocket to increase forgiveness and energy transfer and an extended their pocket cavity for increased stability mizuno engineers were able to re position weight and increase moment of inertia to improve off centre shots increasing ball speed new and improved manufacturing process mizuno has use