Review: Shimano XT M8020 Four-Piston Mountain Bike Brakes Add Stopping Power to Popular M8000s - Singletracks Mountain Bike News
SHIMANO Deore XT BL-M8100/BR-M8120 Disc Brake and Lever - Front, Hydraulic, Post Mount, 4-Piston, Finned Metal Pads, Black : Sports & Outdoors - Amazon.com