High-quality replacement 40mm piston pressure seal designed for StopTech High Performance Brake Calipers (ST-40, ST-60, ST-22). This EPDM rubber seal ensures a leak-proof hydraulic system and proper piston retraction. Kit includes: - 1 x Replacement Piston Seal (40mm ID) - Part No: 753.99005S. Note: This is a single seal. For a complete caliper overhaul, please order the quantity corresponding to the number of 40mm pistons in your specific caliper model.