Race Face Single Rings - Now with performance enhancing chain retention technology. Burly enough for DH Racers and Dirt Jumpers, yet light enough for XC/singlespeed. Single Rings are machined from 7075 aluminium and tested in some of the most punishing riding terrain Built to last.Key Features:Narrow Wide tooth profiling ensures ultimate chain retention,Stiff 4mm plate thickness and I-beam construction transfer loads without flexing,7075-T6 aluminium, aerospace grade strength,Reversible laser etched graphics,Compatible for 9, 10 and 11 speed,Sizes: 30, 32, 34, 36, 38, 104 BCD (4 bolt) ,Weights: 37-57g (36T - 50g).