For serious racers centering on weight financial savings, XRAY's optional CNC-machined braking system disk adapter is CNC-machined from tough 7076 T6 alu, and has now been strategically lightened by 30percent compared to the standard #334140 adapter. Rotating mass is paid off without having to sacrifice energy or durability. Includes factory-pressed pins (non-replaceable). - Lightweight braking system disk adapter - Tough 7075 T6 aluminum - CNC-machined - Strategically lightened by 30%