About this item ZipCore – A lightweight, low-density core sits at the heart of the club. While reducing vibrations and perfecting center of gravity, it also boosts MOI for improved forgiveness on every shot. Hollow Cavity Design – Weight in the toe with a hollow chamber near the heel makes a better, more balanced Wedge that’s forgiving no matter where you strike the face. UltiZip Grooves – Sharper, deeper, and closer together, UltiZip Grooves are more efficient at channeling debris and maximizing spin. Plus, there’s two extra grooves per face for more groove contact across the board. Gelback – A soft, vibration absorbing TPU insert improves feel so even miss-hits are buttery smooth.