2 Piston Vs. 4 Piston MTB Brakes - What's the Difference? | TBS Bike Parts
Amazon.com: SHIMANO Deore XT BL-M8100/BR-M8120 Disc Brake and Lever - Front, Hydraulic, Post Mount, 4-Piston, Finned Metal Pads, Black : Sports & Outdoors
How does the two piston and four piston caliper work? - Quora