Our designers and engineers developed a Panlite window, which is a unique automotive grade polymer, that allows us to showcase the unique topology of the back of the insert. A lightweight steel shaft with 20-30 grams (depending on the grip) of counterbalance weight in the butt end. This is an evolution of our Stroke Lab Weighting that will appeal to even more golfers. These putters all feature a beautiful navy blue PVD finish that really sets them apart and gives them a premium look. Available in 5, 10, 15, and 20 grams these removable weights allow you to dial in your head weight to your exact preference. Weight kit sold separately (available here in December).