T47a Is A Threaded Bottom Bracket Shell Design, Utilizing The Oversized Interface Of Bb Right, But With The Benefit And Peace Of Mind Of A Threaded Interface. Compatible Frames Feature An Asymmetrical 77mm Shell Width, Placing The Non-Drive Side Bearing Within The Frame, And The Drive Side Bearing Externally. Equipped With Precision Dust Covers For A Snug & Secure Fit That Also Fully Protects The Face Of The Bearing Delivers Exceptional Performance Without Any Sacrifices. Ceramicspeed Hand-Built Bearings Carry The Load From Crank To Frame With Un-Paralleled Durability & Efficiency.Bottom Bracket Tool For Installation: Ceramicspeed Dual Socket Tool T45/T47 16-Notch 52,2mm Cup Tool Diameter.Technology:- T45 Was Designed By Colnago To Provide The Design Benefits Of Oversized Bb Shells And The Repair Benefits Of Threaded Bb'S. These Cups And Bearings Adapt The Shell So It Is Compatible With The Sram/Quarq Crank Spindle.- The Frictional Cost Of Our Standard Bearings Is 0.3-.04 Watts. That'S A Reduction Of 75% Compared To Stock Bottom Brackets. This Is The Result Of Hardened-Steel Races Combined With Ceramic Balls That Are 100% Smoother And 15% Harder Than The Ceramic Competition. They Also Last Longer.- Coated Bearings Go Even Longer And Feature Even Less Drag. Life Increases By 60% And Drag Drops By 50% Compared To Our Standard.- All Round Grease Comes Applied To The Bearings. It Can Be Replaced For Lower Drag Race Day Grease, Or Higher Durability Long Life Grease, Which Adds A Bit Of Drag But Stays In When Riding Through Messy Conditions.Maintenance Of Ceramicspeed Headset:- We Recommend That You Follow Our Instructions On How To Maintain Your Ceramicspeed Bottom Brackets To Achieve The Lowest Friction And The Best Longevity.