Quarq sram red dzero 11r 110 hidden bolt road power meter gxp works with sram 11 speed drivetrains and the sram red 10 speed drivetrain available in hidden bolt hb only compatible sram chainrings ensure the chain derailment pin aligns with the crank arm free firmware upgrades with the qalvin ble app bb30 versions ship with the spacers and wave washer required for bb386evo installation size 165mm colour black