Hope Caliper Piston for E4 / V4 / Mono M4 Brake Caliper

Compatibility: Mono M4 2004 and 2007 models (2 x as replacement for the 2 large caliper pistons; for the 2 small caliper pistons, 2 pistons with the manufacturer number HBSP135 are needed) Mono M4 as of 2009 model (4 caliper pistons are required) V4 as of