Adapts 4 piston, Z32 twin turbo aluminum calipers to E46M3 325x28mm rotors on E46M3 front knuckles. CNC aluminum with gold anodizing, laser logos and 12.9 grade hardware. INSTALL NOTES: Top bolt that mounts brackets to knuckles must be installed with bolt head on the outside and nut on the inside to clear the brake pads. The knuckle ears must be ground down flush with the caliper bracket to clear the caliper. Look at the gallery diagram for wheel fitment. The caliper logo (orange point) is closest to the spokes. While the yellow point is closest to the inner wheel barrel. Use the measurements to compare with your own wheel if you remove it from the car, lay it face down and measure the same points distance from the center of the wheel mounting surface. Pair with our reproduction calipers. Pair with our reproduction calipers. Adapt to the the brake lines in the car by adding to cart the lines and fittings set we sell separately, E3646FKCLF.