Shimano saint m810 disc brakes shimanos very first hydraulic disc brake offering was a four piston system but everything since those first deore xt brakes has been two piston for 2009 though saint has gone back to a four pot setup like the venerable xts the saint calipers feature dual diameter pistons resulting in one pair contacting the rotor slightly before the others to improve modulation the brake levers feature the same servo wave design found on the existing xt group packaged into