US Patent 8088025 Golf club head

An iron-type golf club head is disclosed having a heel portion, a sole portion, a toe portion, a top-line portion, a front portion, a rear portion, and a striking face. A back wall is also disclosed in the rear portion enclosing a portion of the rear portion to create an enclosed cavity. The cavity is defined by at least a rear surface of the striking face, an inner back wall surface, and the sole portion. A plug and a filler material is located within the enclosed cavity. The filler material surrounds the plug and is configured to hold the plug in place. The plug is lighter than the filler material.