The SRAM GXP Black Box Ceramic Bottom Bracket Cups, welcome to gutter seal technology. Gutter drastically improves sealing against the elements while reducing seal drag. Sram have designed a fresh new cup forging for a new high end look. A new standard in external bearing performance, now with ultra smooth ceramic bearings that ensure every ounce of your energy translates into on the trail speed. You'll soon be showing you riding partners a fresh set of heels.