You are purchasing 2 sets of pads, enough for a 2-disc motorcycle
The differences: Brembo RC and SC/SR Compound Pads.
SR These pads have been designed to guarantee their users exceptional performance.
Materials of this type are notable mainly for their high friction coefficient and constant efficiency, especially when exposed to high disc temperatures.
These characteristics guarantee an excellent and uniform braking action for the full duration of the race, with less likelihood that fading will occur. Pads of this type provide scant efficiency at lower temperature, a factor of limited importance in racing situations.
Aprilia
BMW
Ducati
Honda
Husqvarna
Kawasaki
KTM
MV Agusta
Suzuki
Triumph