What it is A direct replacement piston rod and two rubber rings for brake caliper maintenance and repair. Package contents 1 piston rod 2 rubber rings Why you need it Restores proper caliper function: replaces worn or damaged piston components to stop sticking, uneven pad wear, and reduced braking response. Maintains brake performance: the precise fit for compatible models helps preserve braking efficiency and modulation. Lightweight impact: the piston rod weighs 5 g, minimizing added weight while keeping the braking system reliable. Compatibility Designed specifically for Shimano M785, M8000, and M7000 systems. Use only with these models for correct fit and function. Key attributes Function: replacement piston rod and sealing rings used when servicing or rebuilding brake calipers. Weight: piston rod is 5 g for a featherlight design that supports overall bike performance. Sealing: includes two rubber rings to restore proper seal and prevent fluid leakage and contamination. Durability: engineered to meet durability and functional standards expected for regular riding and maintenance. How it solves problems Stops brake drag and inconsistent lever feel by replacing worn piston components. Prevents fluid leaks and contamination with new rubber rings, reducing the risk of caliper failure. Keeps your brake system running smoothly without needing a full caliper replacement. Typical use scenarios Routine maintenance: replace the piston and seals when servicing brake calipers to restore factory performance. Trail repair or spare parts kit: carry or store as a lightweight spare for quick fixes after rough rides where pistons or seals may be compromised. Pre-race tune-up: swap in fresh piston and rubber rings to ensure predictable braking and minimal extra weight before competitive events. Notes Intended as a component for calibration, repair, or rebuild of compatible Shimano brake systems listed above. Ensure correct installation and brake bleeding after fitting to restore proper function and safety.