T47 Is A Standard Created By Custom Frame Builders. It'S Threaded, Has An Inner Diameter Of 47mm, And Is 68mm Wide. It Has The Design Benefits Of Being Oversized And Wide, But Also The Practical Benefits Of Threads. Our Gravel Bottom Brackets Are Built With Ceramicspeed Coated Bearings And Equipped With Ufo Long Life Grease For The Ultimate In Durability And Protection In All Environments.The Cups Come With Ceramicspeed Bearings Installed, Coated Bearings And Hardened-Steel Races For Longer Life And Less Bearing Drag.In The Box:- 2 Cups With Ceramicspeed Bearings Installed- 2 Dustcovers- Spacer-Tube- 4 X 1mm Spacers- 2 X 3mm Spacers- Ceramicspeed Long Life Grease- Sticker SheetTech Data:- This Bb Is Compatible With 68mm Frames. - Bottom Bracket Tool For Installation: Bbt-79.Maintenance Of Ceramicspeed Bottom Brackets:- We Recommend That You Follow Our Instructions On How To Maintain Your Ceramicspeed Bottom Brackets To Achieve The Lowest Friction And The Best Longevity.