Full Metal Jacket Designed for mechanical disc brakes What's as efficient as hydraulic fluid? This stainless steel conduit A sealed system with no compression & no friction Zero So your cable-actuated disc brakes will work like new long after some other systems have given up the ghost How do they work? Full Metal Jackets incorporate stainless steel conduit to replace straight runs of housing Do not bend the tubes When routing your FMJs, use traditional housing for bends & the conduit for straight sections Because the tube remains straight, the cable is in the center of the tube when under tension This achieves compressionless, frictionless routing through the FMJs For assistance, refer to your instructions or contact your local bicycle retailer.