The Tektro F10BS Disc Brake Pads are replacement pads for select Tektro flat mount disc brake calipers for road and gravel bikes. The overall balanced resin pad compound has been formulated to deliver reliable braking power in any condition and to be very quiet. These brake pads also use a steel backing plate, and will come with the return spring to ensure the pads will have less contact with the brake rotor. Overall Balanced Resin Compound, For Flat Mount Brakes, Fits HD-R510, HD- R310, and HD-R291