Check the listing for details. Hope EVO GR4 Hydraulic Disc Brake Set Left & Right Post Mount, 4-Piston,. Condition: New. Listed at 575.27 USD. Optimized Hope EVO GR4 Disc Brake and Lever Set Right & Left Hand, Post Mount, 4-Piston, Braided Hydraulic Hose, Black/Orange Ultimate High-Performance Gravity & E-Bike Brake System Enhance your gravity riding and e-bike performance with this premium Hope EVO GR4 Disc Brake and Lever Set, designed for demanding cyclists seeking maximum power, precision control, and reliable stopping performance. Crafted from durable materials with advanced engineering, this 4-piston hydraulic brake system offers industry-leading features to elevate your riding experience on rugged trails, downhill descents, or e-bike adventures. Key Features & Highlights: - **High-Performance 4-Piston Design:** Engineered with larger caliper pistons for increased braking force, delivering bold power ideal for gravity and.