Brembo 19 RCS Adjustable Ratio Radial Brake Master Cylinder - Left Side - Adjustable ratio 18/20 (19x18 or 19x20) - Forged body - Designed for 7/8" sportbike handlebars - For all custom bikes with 2 fixed 4 piston calipers Brembo Radial Master Cylinders are found on the fastest bikes in the world because they're powerful, reliable and built to exacting tolerances for consistent performance under a wide range of conditions. Brembo's 19 RCS master cylinder is no exception. It offers the unique ability to change brake lever ratios from 19x18 (for power) to 19x20 (for feel) with a simple turn of the screw, something not possible on other Brembo brake master cylinders. The 19 RCS is manufactured using a combination of forge-casting and CNC-machining. Forged parts have a particular advantage over parts machined from billet when it comes to strength since the metal's grain structure follows closely the shape of the part as it is pressed into its final form. After forging, the aluminum master cylinder blank is then machined to accept all of its hardware: banjo bolt, brake reservoir spigot, lever attachment and - most critical, the brake piston assembly. This multi-stage manufacturing process ensures both strength, through the forging process and precision via CNC finishing - both of which contribute to the master cylinder's consistent, exacting performance that has made it the "must have" brake upgrade component. Every Brembo 19 RCS master cylinder comes complete with a break-away lever for crash survivability, a dual-line banjo bolt and a micro-switch controller for street applications allowing you to activate the rear brake light without the need to buy a separate pressure-sensitive banjo bolt switch.