The Shimano ST-RX400-R is the right-side shift/brake lever from the GRX 10-speed groupset, tailored specifically for gravel and adventure riding. Designed to work with Shimano’s 10-speed road derailleurs, it delivers reliable mechanical shifting and smooth hydraulic braking in a package that’s ergonomically shaped for off-road control. The textured lever surface and flared hood design improve grip and comfort over rough terrain, while the internal cable routing keeps things tidy. It's a dependable, budget-friendly option for riders building or upgrading a gravel bike with 10-speed capability and hydraulic disc brakes.