The SRAM GXP Black Box Italian Thread Bottom Bracket. Welcome to SRAM's new 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. Giga X Pipe External Bottom Bracket Bearing Assembly. While other systems rely on side loading the bearings to eliminate play, which causes premature bearing wear, the GXP system is different. The GXP system captures the left side bearing between the spindle & the left crankarm while allowing the drive-side bearing to float axially on the spindle, thereby eliminating the necessity to side-load bearings during adjustment. The simplicity of installation is refined: once it is tightened to the proper specifications you are ready to roll with a worry free BB. The GXP system uses two bicycle specific cartridge bearings & eight seals for a smooth & long lasting ride.