It features the robust double-protection of Pro-Tech a patented external sealing ring design protecting a strong, resilient fiberglass-charged polyamide central tube from the harmful ingress of water, mud and grit. The bottom bracket mates with the external stainless steel bearings which are attached to the crank arms as an integral unit rather than the BB cups for greater size and easier maintenance access and sits over a stiff, strong inner axle spindle, delivering performance that is smooth, fluid and predictably consistent from the get-go. Thanks to the Pro-Tech sealing system, it stays that way, however and wherever you ride. Ekar bottom bracket options offer broad compatibility in a full range of threaded and PressFit applications.