RWA1609-4B 23 spline solid hub clutch disc is similar to the 6 puck design except it has organic lining all the way around the disc. Our discs have high strength woven friction material that is bonded to a steel backing plate to provide a high burst strength, smooth engagement, and long service life. We have used both versions of the solid hub disc with great success. We suggest using this type of disc in competition only. If used on a street driven car, you will experience some chatter when taking off from a stop.