Magura MT Caliper Rings Magura's awesome new four-piston design means powerful braking, but it doesn't mean maintenance isn't required to keep the killer calipers running properly. This Four-Piston Caliper Ring set replaces original rings on Magura's caliper assembly. Features Four-piston design replaces standard piston rings on Magura calipers Compatible with:Magura MT5/MT7/MT Trail | Magura | Mt Caliper Rings Mt5/mt7/mt Trail, Neon Blue, Red, Yellow