The 400 Series Disc is intended for the grass roots drag racer. This disc is found in many cars that run in sanctioning bodies that have certain rules that will not allow for the use of fully adjustable clutches and sintered iron discs. This disc is based off of a 10.5" diameter 4 paddle design with ceramic semi metallic pads, flat fin drive plate for quick shifting, a sprung hub with all steel springs. This disc allows you to drive to the track with enough modulation on the street and then beat on the clutch at the track for your best e.t.