The Beringer Aerotec caliper is CNC machined from billet aluminum and anodized for an attractive finish. It's a bolt-on fitment for bikes like the FS450 that use a radial fork bottom. Aerotec Caliper - 4R12A (100mm) Caliper Specs Radial mount bolt orientation with 100mm spacing. Uses 4x 32mm pistons with high performance seals. Can be used with a radial adapter bracket to mount on converted supermoto bikes with axial fork bottoms. USE ONLY DOT 4 RACING BRAKE FLUID Not compatible with DOT 5 fluid. Includes brake pads 1100R2 - Aggressive Race - More bite, best pad for racers! NOT FOR STREET USE! 1100R8 - Endurance Race - less bite, great for rain racing! Longer life, perfect for endurance racing or track day rider who wants more life out of their pads! NOT FOR STREET USE! 1100S - Sport - Perfect for street use, does not require heating up like the race pads. For Single Caliper Use (Supermoto), We Recommend: Beringer Aeronal Cast Iron Rotor Radial mounted caliper offers flexibility for rotor size. Use it with a 310mm rotor, or add spacers to fit a 320mm rotor. Spacer requirements vary depending on application. Beringer Aerotec Master Cylinder Pump For good feel and modulation, we recommend the BRO10 which uses a 14.5mm piston. You can trail on and off the brakes really easy and modulate the brakes with confidence. If you prefer a really stiff lever feel, there are a few riders who like the BRO12 with its 17.5mm piston. However, you do lose some of the feel with this stiff setup.