The BBT-29 is a double-ended bottom bracket wrench designed to fit non-standard diameter 16-notch external bottom bracket bearing cupsOne end fits cups with an outside diameter of 39mm such as Shimano Dura-Ace® 9000 series and XTR® 980 seriesThe other fits 16-notch bearing cups with an outside diameter of 48.5mm such as FSA MegaEvo®Made in the USA and covered by Park Tool's legendary limited lifetime warranty