Wilwood's Stealth Brake System Features: Brakes mount up and inside the fork legs for "invisible" installation. Polished Billet brake bodies. Large 18.75" diameter rotor offers great stopping power and suspension modulation. No rotor or caliper to clutter your custom wheel . With unlimited wheel design possibilities. Works with, or without a fender. Stealth is designed specifically for 21" diameter wheels. Works with the original equipment master cylinder. Custom wheels must be designed to accept Stealth. Required fork brace (truss) is not included.