The Professor SP1R is a 3 piece wheel made using SSRs famed SSF process. The three piece wheel is made up of an outer rim, inner rim, and center disc which allows SSR to offer wide range of offsets and ensures proper fitment specific to your vehicle. The inner rim of the wheel is heat treated for strength, using the HTM (Heat Treatment Manufacture) process which allows for the use of a thinner material to save weight. With weight and high strength in mind, each section of the wheel is engineered using separate grades and thickness of aluminum according to its purpose. SSRs racing heritage and manufacturing innovations have allowed the creation of a 3 piece wheel that is both super lightweight and high in strength.