Cleveland golf has stripped their flagship RTX wedge down to its core and rebuilt it from the inside out. According to Cleveland Golf: "The ZipCore is a low-density material at the heart of RTX. It’s an inside-to-out solution that’s elegant in form and function, with unprecedented results. By replacing heavy steel with a lightweight core, ZipCore repositions mass for kid-in-a candy-shop levels of design freedom. It’s how we pumped in a mountain of High-Low MOI that just wasn’t there b