Magura Two-Piston Caliper Rings Magura is known for making some of the most advanced and powerful brakes on the market, but no brake caliper can perform without proper maintenance. This Two-Piston Caliper Ring set replaces original rings on Magura's caliper assembly to get your brakes running strong like they should after a rebuild. Features Two-piston design replaces standard piston rings on Magura calipers | Magura | Two Pistion Caliper Rings Assorted Colors