US Patent 7281991 Hollow golf club with composite core

A hollow golf club having a hosel sleeve weight made from tungsten material in the upper hosel area and a tungsten toe plug in the lower toe portion of the club head. This combination creates an increase in the moment of inertia of the club head about the x, y and z axes of the club head. A composite core is bladder molded into a cavity in the club head to provide support for a relatively thin front face and the composite core is visible on the rear surface of the club head. The core material is less dense and has greater flexibility than the front face.