Typically unsung, this SRAM GXP Team Bottom Bracket is what you'll find supporting your SRAM road or Truvativ mountain crankset. It's identical to the bottom brackets used in the Force and X0 groups.
SRAM's bottom brackets, while interchangeable between all SRAM and Truvativ cranksets, are brand specific -- meaning, they can only be installed with SRAM cranks. The key element that makes them different from a Shimano or FSA bottom bracket is that the left side bearing has a smaller diameter to mate with the stepped spindle of the SRAM crank. This design allows the inner race of the left side bearing to be captured between the crankarm and the spindle, effectively locating the crank. The right side bearing "floats" on the spindle handling only radial loads as you pedal. The SRAM design optimizes bearing load, minimizes drag, and gives you durability.
The GXP Team Bottom Bracket has alloy cups, anodized in Dark Silver. It's compatible with all SRAM road and Truvativ mountain cranksets. It comes in English threading only and will fit 68mm or 73mm bottom bracket shells (spacers included for 73).