Shimano are calling their new drivetrain technology ... Chain (CN-HG94): The new HG-X 10-speed chains are directional (the right-hand side is optimised for front shifting and the left for rear ...

As you'll come to learn, GRX tends to borrow components from elsewhere in Shimano's range, and 10-speed mechanical borrows a bottom bracket from the Tiagra road range and the cassettes and chains ...