Our ThreadFit(TM) 24 bottom bracket is designed and built to be durable, serviceable, and silent. Manufactured to create the most precise interface between your frame's bottom bracket shell and your cranks, it makes your cranks spin lightly and easily, without interference, for the lifetime of your bike (with a little regular service). King's legendary, angular-contact bearings, both steel and ceramic, are the best in the industry, and actually get faster over time, as their contact surfaces wear. You want this bottom bracket because it offers super low drag. You want this bottom bracket, because it can be opened, cleaned and repacked for years of faithful service. You want this bottom bracket, because you don't want to think an awful lot about your bottom bracket. Our Threadfit(TM) 24 bottom brackets come in an array of beautifully anodized colors and includes a Fit Kit that allows it to be used with a wide selection of road and mountain bike cranks. Specifications - Spindle Interface Type: Shimano Hollowtech II - BB Shell Width (mm): 68 , 73 - Bottom Bracket Shell I.D.: 1.37 - BB/Frame Interface: English