MVP Disc Sports Proton Ion Disc Golf Putter MVP ION - Making its debut in January 2010 the MVP Ion is the first disc from MVP. The Ion's beaded rim design makes it a reliable straight to overstable putter. STABLE-OVERSTABLE PUTTER - Power putters can use the Ion with confidence. The Ion's defining flight characteristic is its straight stable flight with a late subtle fade. 11 MM CLASS - It is capable of holding long powerful lines with a late subtle fade. This makes it a very versatile putter that can be used in all conditions. PROTON PLASTIC - MVPs most premium look and performance materieal. Designed to withstand the roughest conditions with a wide selection of transparent candy colors. PDGA APPROVED - For all professional disc golf play