The Radian was the first return top made by SPYY, released as a limited-production prototype. It was released in early 2006 and was sold directly from the manufacturer's website and on EBay. The return top features a wide, Butterfly-shaped body machined from 6061-T6 aluminum, which is higher in quality than with the standard 6061 alloy. It also features a D-sized EZO bearing, along with recessed Dif Pad response. The first release of twenty-five polished Radians each sold for $55.95 USD and had quickly sold out.