The UUC biggie clutch is 50% larger than stock and it's the ONLY oversized clutch system sold for M5. The larger swept area offers higher torque ratings and better heat management under severe duty. The UUC oversize clutch is the same size as you find in Corvette. The stock M5 240mm (9-5/8") clutch is MUCH smaller than what you find in many 200 HP cars and it's the same size as BMW uses in some low performance 6 cyl gas & diesel cars. The tiny clutch is a chronic problem for many owners who have repeatedly replaced it and absorbed huge labor fees and continue to live with a marginal design that limits performance.
Heavy duty aftermarket clutches in stock size do not meet the needs of certain M5 owners, so this is a welcome niche product. Many folks gladly absorb the extra material cost to achieve a desired result.