Redefining Braking for the MTB Rider. At the heart of this innovative 4-piston brake system lies a formidable 4-piston hydraulic caliper meticulously engineered to provide unmatched stopping power and precision control. Whether navigating steep descents or tackling challenging trails React 4 ensures powerful reliable performance in even the most demanding conditions. Technical specifications Pre-bled and ready to ride Powerful 4 Piston hydraulic brake system Smooth powerful modulated braking Self adjusting 16mm calliper pistons Split-C lever bracket design Lever reach adjustment to suit all hand sizes Suitable for MTB and Hybrid bikes Uses environmentally friendly mineral oil International standard and post mount compatible Stainless steel rotors Spare olives to allow for hose reduction Mineral oil fluid to protect the environment Weight - 315g Complies with and exceeds EN15194 and ISO4210 regulations Box Contents X2 Calipers X2 Levers X2 Rotors and bolts X2 Hoses and all fittings