The Trail S guide is strong enough for the all-mountain rider yet light enough for the weight conscious XC racer. The Trail S is compatible with the XX1 drivetrain as well as older non-clutch rear derailleurs (SRAM Type 2, Shimano Plus) and is perfect for riders with 1x setups looking for chain retention without the weight penalty. The Trail S is available in three sizes (28-32T, 33-36T, 37-40T). The polyurethane sliders and aluminum backplate make for the perfect strength to weight ratio. Silent, simple, and beautiful.