French Design and Manufacturing by Stronglight. Meticulously crafted from the finest materials. Designed around the single chainring philosophy of the XX1 group, the SRAM XX1 11V crankset offers top-level performance. Made from 7075-76 aluminum, the SRAM XX1 chainring is incredibly efficient. The thickness of each tooth is machined with ultra-precision using CNC to fit perfectly with the inner and outer links of the chain. Only compatible with the XX1 crankset due to its specific 76 mm bolt circle diameter, this chainring is available in 6 sizes: 28, 30, 32, 34, 36, and 38. Packaging: 1.