The X9 3x10 High Clamp Front Derailleur shares the same design and principles as SRAM's XO, only it forgoes aluminum in order to keep its price lower. In place of the aluminum, SRAM opted for steel, which adds a little weight but also durability. The cage is specifically designed to work in conjunction with SRAM's 2x10 cranksets and X Glide chainrings. As such, it's designed to handle up to a 15 tooth differential between the big and little rings. The steel links that shape the swing arm of the derailleur cage have widely spaced pivots for increased stiffness. This rigidity, inherent in the parallelogram, is part of what makes X9 front shifting so quick and efficient. The SRAM X0 3x10 High Clamp Front Derailleur is configured to work as either top or bottom pull and is available with 31. 8, 34. 9, and 38. 2mm clamp diameter options.