When Developing These Brake Discs; The Mission Was To Engineer The Highest Quality 2-Piece Brake Discs Possible. These Discs Are Manufactured From The Finest Materials And Consequently Are Some Of The Highest Quality 2-Piece Discs Sold On The Market At Any Price Point. All Outer Friction Rings Are Cast From A High-Copper High-Carbon G3500 Disc Alloy. The Bells Are Precision Machined From Aerospace Grade Aluminium Then Hard Anodised For Great Looks And Excellent Durability. The Cast Iron Outer Ring Floats On Ebc Patented SD-Drive Technology Bobbins; Allowing The Friction Ring To Expand And Contract Freely By Up To 3mm When Subjected To The Extreme Heat Generated From Hard Braking. All Bobbins Are Machined From A Single Piece Of Stainless Steel. This Prevents Unsightly Corrosion And Ensures The Outer Ring Continues To Float Freely Even After Years Of Exposure To The Elements. This Means That Ebc Racings 2-Piece Floating Discs Offer A Low Maintenance Solution That Are At Home On Both The Public Roads And The Race Track. Each Bobbin Location Also Features An Anti-Rattle Spring Clip; Meaning These Discs Are Totally Silent In Operation And Do Not Have The Off Brake Disc Rattle That Plagues Many Other Full Race 2-Piece Disc Systems. Upgrading To An EBC 2-Piece Disc Will Shave Crucial Kilogrammes Off A Vehicles Un-Sprung Rotational Mass; Leading To Sharper Turn In; Improved Tyre Road Holding; Better Fuel Economy And An Increase To Bhp At The Wheels. Best Of All; When The Cast Iron Friction Ring Becomes Worn After A Period Of Use; The Outer Ring Alone Can Be Replaced; Allowing The Centre Hub And Stainless Bobbins To Be Re-Used; Reducing Long Term Running Costs