Replacement seal for HOPE caliper, part number HBSP068. This seal is compatible with M4/Mono M4/E4/V4 calipers. The seal is designed for DOT 4 or DOT 5.1 brake fluid and 16mm HOPE pistons. If you are looking to reseal your brake caliper HOPE your brake, this is exactly what you need. 2 seals are required for 2-piston caliper, 4 seals for 4-piston caliper.