FNSL4R rear big brake kits provide high capacity braking with contemporary styling for high performance street and show Corvettes , and all other custom built vehicles equipped with 1988 - 1996 C4 Corvette rear suspension. The original equipment single piston combination caliper is replaced with a high efficiency, forged aluminum narrow Superlite four - piston caliper for normal braking, and an auxiliary MC4 mechanical caliper for the parking brake. Rotor size is increased from 12.00 to 12.88, adding brake leverage and cooling capacity while complimenting the look inside custom wheel and tire upgrades.