Shimano GRX ST RX400 BR RX400 Hydraulic Disc Brake and Brake Shift Lever SET 2x10 Speed, Flat Mount, Finned Resin Brand_Granite If the system is over Size_27.5 If the system is over 120 kg then an experienced bike mechanic should check the wheel regularly Measurements:250 x 155 mm snap ring Caliper fixing bolt_Tool size 4 mm Fixing screw spec for rear mount_10 mm mount ✔ Fixing screw spec for rear mount_15 mm mount ✔ Fixing screw spec for rear mount_20 mm mount ✔ Fixing screw spec for rear mount_25 mm mount ✔ Fixing screw spec for rear mount_30 mm mount ✔ Fixing screw spec for rear mount_35 mm mount ✔ Hose joint Straight Mount type Flat mount ONE WAY BLEEDING ✔ Pad mount Pad axle Piston 2 Recommended brake lever ST RX400 Recommended disc brake rotor SM RT64 J Kit spec (for OEM) ✔ Oil SHIMANO Mineral Pad_Option 1 K04S MX Metal (w o fin) Pad_Option 2 L04C MF Metal (w fin) Pad_Standard 1 K05S RX Resin (w o fin) Pad_Standard 2 L05A RF Resin (w fin) MODEL NO BR RX400 R SERIES GRX 10 speed Color Series color Remarks Front spec with adaptor