The Diablo Octane Fairway Woods are available in 3, 5, 7 and 9 woods. The steel head and incorporates an improved version of Callaway’s Variable Face Thickness technology to alter the internal thickness of the face for a larger sweet spot. The clubhead of the Callaway Diablo Octane Fairway Wood is heat treated for enhanced strength and durability for what Callaway claim is longer, higher shots from the fairway as well as the tee. The looks of the Diablo Octane fairway wood are classic Callaway with a slightly closed face and short hosel that goes into the heel of the crown. However if you can put that aside, you have a very competent club with a oversized rounded head that offers a good level of forgiveness and a solid sound and feel, even if it is a bit on the muted side.