Cobra Men's Fly-Z XL Golf Iron Combo Set, Right Hand, Regular, 4-6H, Graphite Hybrids, Steel Irons, 4-GW Speed Channel Face: An engineered trench behind the face area helps to minimize face thickness and increase flexion Dual Cavity Hollow Design: 7 and 8 iron feature a dual cavity to create a lower & deeper CG that delivers easy launch with extreme forgiveness Perimeter Undercutting: (9 - SW)-Removes weight from the back of entire face area to create a large undercut for forgiveness in scoring irons Speed Channel Face In Hybrids: An engineered trench around the perimeter of the face thins the wall structure around the perimeter to increase Speed Zone Weighting Technology in Hybrids removes weight from the crown to reposition low and back in the head for a Low deep CG