Original Shimano GRX hydraulic brake sublevers. installs into existing system with ease (not need to remove existing brake hoses) provides more comfort and safety when riding upright. Beaking power the same as main levers as they part of the same system.
bought two sets, haven’t got time to install the second set for my wife as she sold her gravel in favor of road bike.
New and unused, original invoice from BikeDiscount available.