Can be used in the rear of open wheel modifieds and street stocks racing on dirt surfaces to increase rear brake bias. Can be used on the front of open wheel modifieds and street stocks racing on pavement surfaces. Oversize 2 3/4" piston provides approximately 20% more caliper clamping force for increased brake bias. Increases range of brake bias adjustment for better brake performance. Allows for more brake system tune ability. Assembled with new piston and internal parts. Quality control checked and pressure tested. Stock appearing . 6.620 lbs. Mounting Center 5 1/2"