I replaced the rear calipers on a 04 arctic cat 500 ATV 4x4 . The calipers were a exact match except for the bleed screw. The bleed screw actually hits the inside of the wheel. The calipers that I see on line that were supposed to fit ,do not even come close to looking the same. Was there a redesign of the calipers. OEM HAS TWO PISTONS.