ADVICS BMT-166 Brake Master Cylinder OEM style reservoir connection ensures a leak-free seal and prevents contamination Like metals and technically advanced components prevents chemical reaction that may lead to corrosion and early failure Ultra-smooth cylinder bore finish maximizes performance resulting in longer service life for reliable braking Ethylene Propylene Rubber (EPDM) prevents leakage and has superior resistance to heat and corrosion Precise fit and longer life